Cross-compiling the MongoDB C Driver for Windows x64 on Linux with MinGW-w64 fails because several Windows header and library references use mixed-case names. These do not match the lowercase filenames provided by MinGW-w64 on a case-sensitive filesystem.

Affected references:

• Headers: WinDNS.h, Windows.h, Mstcpip.h
• Libraries: Bcrypt.lib, Shlwapi.lib, Dnsapi, DbgHelp.lib

Steps to reproduce:
1. Configure CMake on Linux with a MinGW-w64 toolchain targeting Windows x64.
2. Enable Windows native TLS, SSPI, SRV, and tests:

• ENABLE_SSL=WINDOWS
• ENABLE_SASL=SSPI
• ENABLE_SRV=ON
• ENABLE_TESTS=ON
  3. Build the libraries and the test-libmongoc target.

Actual result:
Compilation fails with missing-header errors. After correcting the header names, linking fails to locate the mixed-case library names. The BCryptDeriveKeyPBKDF2 feature check also incorrectly reports the function as unavailable because it cannot link Bcrypt.lib.

Expected result:
The project builds successfully using the Windows headers and import libraries supplied by MinGW-w64.

Proposed fix:
Use lowercase Windows header and library names compatible with MinGW-w64 on case-sensitive filesystems.

Validation:
With these changes, Windows x64 static libraries, DLLs, and test-libmongoc build successfully with both the native Windows TLS backend and an existing MinGW OpenSSL installation. Each configuration passes 46 selected tests under Wine; four server-dependent authentication tests are skipped. The full test suite and native Windows runtime behavior have not been verified.