Hack to inject -lstdc++fs for lang/gcc

Index: StandAlone/CMakeLists.txt
--- StandAlone/CMakeLists.txt.orig
+++ StandAlone/CMakeLists.txt
@@ -66,7 +66,7 @@ if(WIN32)
     set(LIBRARIES ${LIBRARIES} psapi)
 elseif(UNIX)
     if(NOT ANDROID AND NOT QNX)
-        set(LIBRARIES ${LIBRARIES} pthread)
+        set(LIBRARIES ${LIBRARIES} pthread ${ADDITIONAL_LIBRARIES})
     endif()
 endif()
 
