hg: build-infra/jdk9/hotspot: Improve behavior of new feature-based build.

[magnus.ihse.bursie at oracle.com]

Changeset: 936ae7a04bca
Author:    ihse
Date:      2015-10-09 17:04 +0200
URL:       http://hg.openjdk.java.net/build-infra/jdk9/hotspot/rev/936ae7a04bca

Improve behavior of new feature-based build.

! makefiles/BuildHotspot.gmk
! makefiles/JvmFeaturesConf.gmk
! makefiles/JvmPlatformsConf.gmk