Fixed: PCH with old CMake versions (definitions already include -D)

--HG--
branch : develop

code/CMakeModules/PCHSupport.cmake

@@ -179,16 +179,18 @@ MACRO(PCH_SET_COMPILE_FLAGS _target)
     GET_DIRECTORY_PROPERTY(_DIRECTORY_FLAGS DEFINITIONS)
 
     IF(_DIRECTORY_FLAGS)
+      SEPARATE_ARGUMENTS(_DIRECTORY_FLAGS)
       FOREACH(item ${_DIRECTORY_FLAGS})
-        LIST(APPEND _FLAGS "$<$<BOOL:${item}>:-D$<JOIN:${item},-D>>")
+        LIST(APPEND _FLAGS "${item}")
       ENDFOREACH()
     ENDIF()
     
     GET_DIRECTORY_PROPERTY(_DIRECTORY_DEFINITIONS DIRECTORY ${CMAKE_SOURCE_DIR} DEFINITIONS)
 
     IF(_DIRECTORY_DEFINITIONS)
+      SEPARATE_ARGUMENTS(_DIRECTORY_DEFINITIONS)
       FOREACH(item ${_DIRECTORY_DEFINITIONS})
-        LIST(APPEND _FLAGS "$<$<BOOL:${item}>:-D$<JOIN:${item},-D>>")
+        LIST(APPEND _FLAGS "${item}")
       ENDFOREACH()
     ENDIF()
   ENDIF()