Allow parallel build of native and bytecode stubs of the systhreads library. (#811)
Allow parallel build of native and bytecode stubs of the systhreads library. (#811)

Before this commit, it was not possible to build the object files for
st_stubs_b and st_stubs_n in parallel, because both builds were performed
by first building an st_stubs object file and then renaming it, resulting
in a filename clash in case of parallel build.

This commit fixes this situation by giving the C compiler the right options
so that object files are created with the right name from the beginning
and do not need to be renamed afterwards.
yunxing/ocaml,yunxing/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,yunxing/ocaml,msprotz/ocaml,msprotz/ocaml,yunxing/ocaml,msprotz/ocaml