HIP, Windows: Add Windows-Clang-HIP platform module

Merged Mészáros Gergely requested to merge Maetveis/cmake:hip_windows_platform_module into master

Add a platform module for using clang for HIP on windows, based on the CXX module.

HIP language on windows works without this, but mixing with MSVC produces catastrofical results. Add the same restriction with HIP as C and C++ had prior: Either none are compiled with MSVC or all are.

clang-cl support for HIP does not work yet: it needs more work in both hip-lang-config.cmake and cmake itself.

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