hg: build-infra/jdk9/hotspot: Split out mapfile generation to separate file.

[magnus.ihse.bursie at oracle.com]

Changeset: 657e66116d21
Author:    ihse
Date:      2015-11-10 23:32 +0100
URL:       http://hg.openjdk.java.net/build-infra/jdk9/hotspot/rev/657e66116d21

Split out mapfile generation to separate file.

! makefiles/CompileJvm.gmk
+ makefiles/CreateMapfile.gmk