Buildsystem: Initial changes to support building with vs clang toolset

cmake/macros/FindPCHSupport.cmake

@@ -150,7 +150,7 @@ FUNCTION(ADD_CXX_PCH_XCODE TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
 ENDFUNCTION(ADD_CXX_PCH_XCODE)
 
 FUNCTION(ADD_CXX_PCH TARGET_NAME_LIST PCH_HEADER PCH_SOURCE)
-  IF (MSVC)
+  IF (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
     ADD_CXX_PCH_MSVC("${TARGET_NAME_LIST}" ${PCH_HEADER} ${PCH_SOURCE})
   ELSEIF ("${CMAKE_GENERATOR}" MATCHES "Xcode")
     ADD_CXX_PCH_XCODE("${TARGET_NAME_LIST}" ${PCH_HEADER} ${PCH_SOURCE})