compilerDefinitions.cmake: actually define _LIBCPP_REMOVE_TRANSITIVE_INCLUDES for all libc++ builds (danmar#7429)

Author: firewave

cmake/compilerDefinitions.cmake

@@ -22,14 +22,17 @@ if(CPPCHK_GLIBCXX_DEBUG AND UNIX AND CMAKE_BUILD_TYPE STREQUAL "Debug")
                 add_definitions(-D_LIBCPP_ENABLE_ASSERTIONS=1)
             endif()
             # TODO: also add _LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS?
-            add_definitions(-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES)
         endif()
     else()
         # TODO: check if this can be enabled again for Clang - also done in Makefile
         add_definitions(-D_GLIBCXX_DEBUG)
     endif()
 endif()
 
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND USE_LIBCXX)
+    add_definitions(-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES)
+endif()
+
 if(HAVE_RULES)
     add_definitions(-DHAVE_RULES)
 endif()