hg: jdk9/sandbox: 8139272: Add configure variable to set concurrency for jtreg tests

[chris.hegarty at oracle.com]

Changeset: e79b5043fd02
Author:    ehelin
Date:      2015-12-15 11:04 +0100
URL:       http://hg.openjdk.java.net/jdk9/sandbox/rev/e79b5043fd02

8139272: Add configure variable to set concurrency for jtreg tests
Reviewed-by: erikj, ihse

! common/autoconf/build-performance.m4
! common/autoconf/configure.ac
! common/autoconf/generated-configure.sh
! common/autoconf/spec.gmk.in
! make/Help.gmk
! make/InitSupport.gmk
! make/MainSupport.gmk
! test/Makefile