Make the ParserSync test faster (and re-enable it).

Most of the run time came from testing with all possible flag combinations. None
of the flags passed affect the test, and there are specialized tests for testing
the features behind the flags; no need to slow down the generic test.

With these changes, run time for debug build goes from 186 s to 0.5 s.

In addition, fixed some missing commas between the test cases.

R=svenpanne@chromium.org
BUG=v8:3707
LOG=N

Review URL: https://codereview.chromium.org/766673003

Cr-Commit-Position: refs/heads/master@{#25612}