[test] Disable two more failing tests.

TBR=jarin@chromium.org
NOTREECHECKS=true
BUG=v8:4493
LOG=n
NOTRY=true

Review URL: https://codereview.chromium.org/1413223007

Cr-Commit-Position: refs/heads/master@{#31425}

test/mjsunit/mjsunit.status

@@ -357,6 +357,10 @@
   'json': [PASS, SLOW],
   'regress/regress-446389': [PASS, SLOW],
   'regress/regress-inline-getter-near-stack-limit': [PASS, SLOW],
+
+  # BUG(v8:4493).
+  'accessor-map-sharing': [PASS, NO_VARIANTS],
+  'tools/profviz': [PASS, NO_VARIANTS],
 }],  # 'gc_stress == True'
 
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