RFR: 9+8u: Remove stray include mman.h

[Aleksey Shipilev]

This is not available on Windows, obviously. And we don't need it in Shenandoah
code, because os::protect_memory does the OS-specific stuff for us.

$ hg diff
diff -r e17250b1955f src/share/vm/gc/shenandoah/shenandoahHeapRegion.cpp
--- a/src/share/vm/gc/shenandoah/shenandoahHeapRegion.cpp	Tue Mar 21 21:34:20
2017 +0100
+++ b/src/share/vm/gc/shenandoah/shenandoahHeapRegion.cpp	Tue Mar 21 21:35:08
2017 +0100
@@ -126,8 +126,6 @@
 #endif
 }

-#include <sys/mman.h>
-
 #ifdef ASSERT

 void ShenandoahHeapRegion::memProtectionOn() {


Testing: hotspot_gc_shenandoah

-Aleksey