[tests] Skip mjsunit/es6/block-conflicts in GC stress mode.

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1694443003 .

Cr-Commit-Position: refs/heads/master@{#33928}

test/mjsunit/mjsunit.status

@@ -353,6 +353,9 @@
   # TODO(jkummerow): Doesn't work correctly in GC stress.
   'regress/regress-crbug-500497': [SKIP],
 
+  # TODO(turbofan): Seems related to try-catch/try-finally in TF.
+  'es6/block-conflicts': [NO_VARIANTS],
+
   # Too slow for gc stress.
   'asm/embenchen/box2d': [SKIP],