Add infrastructure for skipping tests in GC stress mode.

test/mjsunit/array-feedback.js

Index: test/mjsunit/array-feedback.js
diff --git a/test/mjsunit/array-feedback.js b/test/mjsunit/array-feedback.js
index 0471f65f40d039858197f5e73b23b5324969a896..4129be1f880cb7974ec15d784707b1e2412fea0f 100644
--- a/test/mjsunit/array-feedback.js
+++ b/test/mjsunit/array-feedback.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;