hg: shenandoah/jdk9/hotspot: Remove stray include mman.h.

[ashipile at redhat.com]

Changeset: 240825262ade
Author:    shade
Date:      2017-03-21 21:46 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk9/hotspot/rev/240825262ade

Remove stray include mman.h.

! src/share/vm/gc/shenandoah/shenandoahHeapRegion.cpp