[11u] RFR: 8256810: Incremental rebuild broken on Macosx

[Roland Westrelin]

Hi Martin,

> JDK-8256810 is backported to 11.0.11-oracle. I'd like to backport it for parity.
> Change doesn't apply cleanly because of an unlrelated context change (Solaris removal).

See my RFR for the backport of 8257547. It basically replaces all of
that code.

Roland.