hg: build-infra/jdk9: * List available features in configure --help.

[magnus.ihse.bursie at oracle.com]

Changeset: bfd15457aae1
Author:    ihse
Date:      2016-02-09 16:19 +0100
URL:       http://hg.openjdk.java.net/build-infra/jdk9/rev/bfd15457aae1

* List available features in configure --help.
* Start moving feature validation into configure.

! common/autoconf/configure
! common/autoconf/generated-configure.sh
! common/autoconf/help.m4
! common/autoconf/hotspot.m4
! common/autoconf/spec.gmk.in