[turbofan] Disable two more failing tests.

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

Review URL: https://codereview.chromium.org/1412573005

Cr-Commit-Position: refs/heads/master@{#31423}

test/mjsunit/mjsunit.status

@@ -153,6 +153,7 @@
   'regress/regress-1122': [PASS, NO_VARIANTS],
 
   # Issue 4493: Bugs due to --turbo-inlining.
+  'sparse-array-reverse': [PASS, NO_VARIANTS],
   'harmony/reflect': [PASS, NO_VARIANTS],
 
   # Assumptions about optimization need investigation in TurboFan.
@@ -276,7 +277,8 @@
   'readonly': [PASS, SLOW],
   'regress/regress-1200351': [PASS, ['mode == debug', SLOW]],
   'regress/regress-crbug-474297': [PASS, ['mode == debug', SLOW]],
-  'strong/implicit-conversions': [PASS, SLOW],
+  # Issue 4493: The 'implicit-conversions' is only NO_VARIANTS because of 4493.
+  'strong/implicit-conversions': [PASS, SLOW, NO_VARIANTS],
   'strong/load-element-mutate-backing-store': [PASS, SLOW],
 }],  # ALWAYS