Build the Windows client against the MSVC ABI while retaining clang
language support. Use vcpkg for ANGLE and libsamplerate, and build
MsQuic with its bundled static OpenSSL.
Build MsQuic's component archives instead of flattening Windows import
libraries into the monolithic archive. Use the static OpenSSL archives
supplied by the active MinGW toolchain while retaining Schannel for MSVC
and QuicTLS for Linux.
Let the active compiler locate its target root and use the restricted
ntdll import library. Provide GCC-compatible byte interlocked
operations, expose native XDP calls, and suppress expected compatibility
warnings.
