RFR(XS) 8098552: 8079792 breaks Zero builds without precompiled headers.

[Severin Gehwolf]

Hi,

Could somebody please review and sponsor this trivial fix? The issue is
that the Zero build fails with precompiled headers turned off (other
builds probably too, but I haven't checked). The fix is to include
memRegion.hpp in g1/g1BiasedArray.hpp since it uses MemRegion.

Bug: https://bugs.openjdk.java.net/browse/JDK-8098552
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8098552/webrev.01/

Thanks,
Severin