Please review this fix to make the build compatible with GNU make 4.3.
See bug for details on the fix, but this change basically adds an empty
rule like this for the example failure:
/localhome/git/jdk-sandbox/open/build/linux-x86_64-server-release/buildtools/langtools_tools_classes/_the.BUILD_TOOLS_LANGTOOLS.vardeps:
With this change I'm able to build with make 4.3 and DependOnVariable is
still behaving as expected.
Webrev: http://cr.openjdk.java.net/~erikj/8237879/webrev.01/index.html
Bug: https://bugs.openjdk.java.net/browse/JDK-8237879
/Erik
