Various run-test makefile fixes.

Reduce number of test combinations based on global flags, rather than just
specific tests, to keep known broken list as small as possible.
Fix dist goal known broken definition.
Fix naming of rules in define-test-art-run-test to match the make target.
Undefine more variables after use.

Change-Id: I4b4eadd37fc1f816bc61d78c5866bfcee7b60244