art/test: support sequential run

Introduce --seq option for art/test/run-all-tests.
This option runs tests one-by-one, avoiding failures
caused by busy CPU

Change-Id: Ibe29f749d267fb05dff4617787c7afcbdbeb43c0
Signed-off-by: Dmitry Petrochenko <dmitry.petrochenko@intel.com>
diff --git a/Android.mk b/Android.mk
index 92339af..01819ee 100644
--- a/Android.mk
+++ b/Android.mk
@@ -63,7 +63,7 @@
 	rm -f $(2ND_TARGET_OUT_INTERMEDIATES)/JAVA_LIBRARIES/*_intermediates/javalib.odex
 	rm -f $(2ND_TARGET_OUT_INTERMEDIATES)/APPS/*_intermediates/*.odex
 endif
-	rm -rf /tmp/test-*/dalvik-cache/*
+	rm -rf /tmp/$(USER)/test-*/dalvik-cache/*
 	rm -rf /tmp/android-data/dalvik-cache/*
 
 .PHONY: clean-oat-target