igc, macOS avoiding signals

[Gerd Möllmann]

This is about commit

ceec5ace134081b64dbf46c4fb5702ef5209c5fd
Avoid MPS being interrupted by signals

I've been running with this for some days now, and must report that
Emacs feels a _bit_ different here in interactive use, maybe one could
say not as smooth. (macOS, --without-ns, in my fork of Emacs, which is
very recent master++).

After reverting the commit, it's feeling smoother again.

Just saying. FWIW.

Maybe it's a point for making things conditional on OS, don't know.