Disable webkit/array-iterate-backwards test in --gc-stress mode for turbofan

test/webkit/webkit.status

Index: test/webkit/webkit.status
diff --git a/test/webkit/webkit.status b/test/webkit/webkit.status
index 3bb6574dde1374ba0bdb68c61d482ce063ff1ff5..9f9ee11d790802ee82a2e501002e5fc0865dd6e5 100644
--- a/test/webkit/webkit.status
+++ b/test/webkit/webkit.status
@@ -59,5 +59,10 @@
   'fast/js/excessive-comma-usage': [SKIP]
 }],  # 'gc_stress == True'
 
+['gc_stress == True and mode == debug', {
+  # Skip tests that timout with turbofan.
+  'array-iterate-backwards': [PASS, NO_VARIANTS]
+}],  # 'gc_stress == True and mode == debug'
+
 ##############################################################################
 ]