build-infra: Linker warnings on macosx

On macosx, we get lots of lines like this:

ld: warning: ignoring file /HUDSON/workspace/2-build-macosx-x86_64/jdk8-newmake/1571/build/macosx-x86_64/jdk/objs/libfdlibm/e_acos.o, file was built for unsupported file format which is not the architecture being linked (i386)

This looks weird but old build system did the same. Nevertheless, it might be that we add files that does not need linking, and if we remove those from the command line we can reduce clutter.