only set VMPROF_APPLE on darwin

Merged nimaje requested to merge branch/set-vmprof_apple-only-on-darwin into branch/default

setting that on all systems that aren't handled explicitly breaks translation at least on freebsd, but probably on everything that isn't darwin (wanted there), linux or windows (handled explicitly).

--HG-- branch : set-vmprof_apple-only-on-darwin

Merge request reports