force c++ for c++ files

Modules/Platform/Windows-cl.cmake

@@ -29,7 +29,7 @@ SET(CMAKE_C_CREATE_STATIC_LIBRARY ${CMAKE_CXX_CREATE_STATIC_LIBRARY})
 
 # compile a C++ file into an object file
 SET(CMAKE_CXX_COMPILE_OBJECT
-    "<CMAKE_CXX_COMPILER>  ${CMAKE_START_TEMP_FILE} /nologo -DWIN32 /Fo<OBJECT> <FLAGS> -c <SOURCE>${CMAKE_END_TEMP_FILE}")
+    "<CMAKE_CXX_COMPILER>  ${CMAKE_START_TEMP_FILE} /nologo /TP -DWIN32 /Fo<OBJECT> <FLAGS> -c <SOURCE>${CMAKE_END_TEMP_FILE}")
 
 # compile a C file into an object file
 SET(CMAKE_C_COMPILE_OBJECT