Zig unconditionally passes -nostdinc++ and adds its bundled
libc++/libc++abi include paths, which conflict with MSVC's own C++
runtime headers. The MSVC SDK directories (added via linkLibC)
already contain both C and C++ headers, so linkLibCpp is not needed.
This is the same fix already applied upstream to highway, simdutf,
utfcpp, glslang, SharedDeps, and GhosttyZig.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>