RFR: JDK-8136378 Build test libs using properly integrated makefile

Fri Sep 11 13:16:06 UTC 2015

Currently there is a (broken) ad-hoc solution to build wb.jar and 
test-lib.jar from sources in $TOP/test/lib.

This should be replaced by a proper make target and using the 
build-infra framework.

Bug: https://bugs.openjdk.java.net/browse/JDK-8136378
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8136378-use-proper-make-for-testlibs/webrev.01

/Magnus