Fix command-line for MSVC
Fix command-line for MSVC

Avoid warnings when calling the MS C compiler from an OCaml driver:

 - #7078: Do not pass -g.  One could perhaps pass /Zi, but it is not
clear this would be useful.

 - Use /Fo instead of the deprecated -o to specify the output object
file,

gerdstolpmann/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,msprotz/ocaml,yunxing/ocaml,yunxing/ocaml,msprotz/ocaml,eliberis/ocaml,eliberis/ocaml,eliberis/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,msprotz/ocaml,eliberis/ocaml,msprotz/ocaml