Reland of d8 workers: make sure Shell::Quit is only called once

test/mjsunit/mjsunit.status

Index: test/mjsunit/mjsunit.status
diff --git a/test/mjsunit/mjsunit.status b/test/mjsunit/mjsunit.status
index 864cd3ee31b307bc014385ad09d69bb1aa7dfe90..0b25f4c65b62510e01481729704e5d4b5f28b809 100644
--- a/test/mjsunit/mjsunit.status
+++ b/test/mjsunit/mjsunit.status
@@ -248,9 +248,6 @@
   # BUG(chromium:508074). Remove this once the issue is fixed.
   'harmony/arrow-rest-params': [PASS, NO_VARIANTS],
   'harmony/rest-params': [PASS, ['no_snap == True', NO_VARIANTS]],
-
-  # BUG(v8:4279).
-  'regress/regress-4279': [PASS, ['isolates', SKIP]],
 }],  # ALWAYS
 
 ['novfp3 == True', {