[test] Skip slow tests for deopt fuzzer.

TBR=ishell@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1834083002

Cr-Commit-Position: refs/heads/master@{#35078}

test/mjsunit/mjsunit.status

@@ -735,6 +735,9 @@
 
   # Deopt every n garbage collections collides with deopt every n times.
   'regress/regress-2653': [SKIP],
+
+  # Too slow.
+  'es6/tail-call-megatest*': [SKIP],
 }],  # 'deopt_fuzzer == True'
 
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