I just downloaded the ZIP you linked in your message....
It built as a 32 bit static library on Pelles C 7 x64 ...
But it was not without a lot of warnings...
Building sqlite3.obj. Use <stdlib.h> instead of non-standard <malloc.h>
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(20969): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(20962): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(20970): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(20968): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(21425): warning #2071: Overflow in constant expression.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'AreFileApisANSI' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'CloseHandle' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'CreateFileA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'CreateFileW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'CreateFileMappingA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'CreateFileMappingW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'CreateMutexW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'DeleteFileA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'DeleteFileW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'FlushFileBuffers' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'FormatMessageA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'FormatMessageW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'FreeLibrary' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetCurrentProcessId' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetDiskFreeSpaceA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetDiskFreeSpaceW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetFileAttributesA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetFileAttributesW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetFileAttributesExW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetFileSize' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetFullPathNameA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetFullPathNameW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetLastError' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetProcAddress' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetSystemInfo' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetSystemTime' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetSystemTimeAsFileTime' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetTempPathA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetTempPathW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetTickCount' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetVersionExA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapAlloc' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapCreate' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapDestroy' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapFree' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapReAlloc' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapSize' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'HeapValidate' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'LoadLibraryA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'LoadLibraryW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'LocalFree' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'LockFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'LockFileEx' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'MapViewOfFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'MultiByteToWideChar' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'QueryPerformanceCounter' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'ReadFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'SetEndOfFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'SetFilePointer' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'Sleep' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'SystemTimeToFileTime' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'UnlockFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'UnlockFileEx' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'UnmapViewOfFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'WideCharToMultiByte' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'WriteFile' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'WaitForSingleObject' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'OutputDebugStringA' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'OutputDebugStringW' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(31001): warning #2214: Address of import 'GetProcessHeap' is not static, identity not guaranteed.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(43010): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(43011): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(43012): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(43013): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(43015): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(43016): warning #2154: Unreachable code.
D:\Coding\sqlite-amalgamation-3071501\sqlite-amalgamation-3071501\sqlite3.c(8153): warning #2135: Static 'sqlite3one' is not referenced.
Building sqlite.lib.
Done.
Thing is, you need to deal with the warnings as though they're errors...
Moreover, Pelles C does not "smart link" so having all your functions in one giant source code means that whole thing is going to be linked into whatever executable you are creating. You might be better to find the standard multi-source version and try compiling it.
In any event... this is not a bug in Pelles C.