hg: build-infra/jdk8: More configure.ac splitting. Moving alt/override-sourceroot stuff to

[magnus.ihse.bursie at oracle.com]

Changeset: 608120f8f364
Author:    ihse
Date:      2012-06-11 16:57 +0200
URL:       http://hg.openjdk.java.net/build-infra/jdk8/rev/608120f8f364

More configure.ac splitting. Moving alt/override-sourceroot stuff to
source-tree.m4.

+ common/autoconf/configure.ac
! common/autoconf/generated-configure.sh
! common/autoconf/source-tree.m4 < common/autoconf/configure.ac