hg: build-infra/jdk8/langtools: * Since repo-specific Makefiles can't be run standalone, rename them to Build<Repo>.gmk.

[magnus.ihse.bursie at oracle.com]

Changeset: 6d33f175e3e4
Author:    ihse
Date:      2012-10-10 22:36 +0200
URL:       http://hg.openjdk.java.net/build-infra/jdk8/langtools/rev/6d33f175e3e4

* Since repo-specific Makefiles can't be run standalone, rename them to Build<Repo>.gmk.
* Create simple Makefile in each repo that calls top-level Makefile with current repo as target.

+ makefiles/BuildLangtools.gmk
! makefiles/Makefile