Build glib on x86-linux

[koprok]

Changes to build glib on x86-linux target. The following triplet file has been used for the build:

set(VCPKG_TARGET_ARCHITECTURE x86)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE static)

set(VCPKG_CMAKE_SYSTEM_NAME Linux)

set(VCPKG_C_FLAGS "-m32")
set(VCPKG_CXX_FLAGS "-m32")
set(VCPKG_LINKER_FLAGS "-m32")

[ras0219-msft]

Thank for the PR! LGTM pending CI.

We generally try to make the CMake files as vcpkg-independent as possible, so I've pulled some of the CFLAGS detection logic over from our boost wrapper[1] which should be more robust :)

[1] https://github.com/Microsoft/vcpkg/blob/6509199a2aeb882c91babb7cc95ef36b30738091/ports/boost-modular-build-helper/CMakeLists.txt#L44-L60

[vicroms]

Thanks for the PR!
It passes all CI tests! 🎉