hg: jdk8u/jdk8u-dev: 8031759: Improved tool overriding in configure

[kevin.walls at oracle.com]

Changeset: 0e87966d7ff1
Author:    kevinw
Date:      2018-03-20 09:19 -0700
URL:       http://hg.openjdk.java.net/jdk8u/jdk8u-dev/rev/0e87966d7ff1

8031759: Improved tool overriding in configure
Reviewed-by: ihse, tbell, mduigou, erikj

! common/autoconf/basics.m4
! common/autoconf/build-performance.m4
! common/autoconf/configure
! common/autoconf/generated-configure.sh
! common/autoconf/toolchain.m4