Add infrastructure for skipping tests in GC stress mode.

test/mjsunit/opt-elements-kind.js

Index: test/mjsunit/opt-elements-kind.js
diff --git a/test/mjsunit/opt-elements-kind.js b/test/mjsunit/opt-elements-kind.js
index a7811c81eafa87266e96374a6aec90ccf74cecf7..f26bb4206778bfe7bda6129b7d4e66eae8edb5c2 100644
--- a/test/mjsunit/opt-elements-kind.js
+++ b/test/mjsunit/opt-elements-kind.js
@@ -39,11 +39,6 @@
 // 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));
 
 if (support_smi_only_arrays) {