Bug 612677 - Accept TEST_PATH as an environment variable for crashtest and jstestbrowser. r=khuey a=NPOTB

testing/testsuite-targets.mk

@@ -113,12 +113,12 @@ reftest:
 	$(call RUN_REFTEST,$(topsrcdir)/$(TEST_PATH))
 	$(CHECK_TEST_ERROR)
 
-crashtest: TEST_PATH=testing/crashtest/crashtests.list
+crashtest: TEST_PATH?=testing/crashtest/crashtests.list
 crashtest:
 	$(call RUN_REFTEST,$(topsrcdir)/$(TEST_PATH))
 	$(CHECK_TEST_ERROR)
 
-jstestbrowser: TEST_PATH=js/src/tests/jstests.list
+jstestbrowser: TEST_PATH?=js/src/tests/jstests.list
 jstestbrowser:
 	$(call RUN_REFTEST,$(topsrcdir)/$(TEST_PATH) --extra-profile-file=$(topsrcdir)/js/src/tests/user.js)
 	$(CHECK_TEST_ERROR)