Can't generate shared library on linux gcc when map file generation feature is turned on

[shiluotang]

The log says:

[INFO] Starting link {4.8 -shared -M -shared-libgcc}
[WARNING] g++: warning: /home/xxx/yyy/zzz/target/nar/obj/amd64-Linux-gpp/core.e06dac6f.o: linker input file unused because linking not done

Actually the -M option is for ld. It can't be processed directly by gcc or g++ unless it's passed through -Xlinker option