Add infrastructure for skipping tests in GC stress mode.

test/mjsunit/allocation-site-info.js

Index: test/mjsunit/allocation-site-info.js
diff --git a/test/mjsunit/allocation-site-info.js b/test/mjsunit/allocation-site-info.js
index 7885608c31623e490780bedb794a0383fd30ccf1..cd086d35060355e97a37f7f6aba8886d9660baea 100644
--- a/test/mjsunit/allocation-site-info.js
+++ b/test/mjsunit/allocation-site-info.js
@@ -35,11 +35,6 @@
 // in this test case.  Depending on whether smi-only arrays are actually
 // enabled, this test takes the appropriate code path to check smi-only arrays.
 
-// Reset the GC stress mode to be off. Needed because AllocationMementos only
-// live for one gc, so a gc that happens in certain fragile areas of the test
-// can break assumptions.
-%SetFlags("--gc-interval=-1")
-
 // support_smi_only_arrays = %HasFastSmiElements(new Array(1,2,3,4,5,6,7,8));
 support_smi_only_arrays = true;