In some cases, PreParser cannot replicate the Scope structure created by
Parser. It happens esp. with arrow function parameters, since the relevant
information is already lost by the time we figure out it's an arrow function.

In these cases, PreParser should bail out of trying to create data for skipping
inner functions.

Implementation notes:

- The arrow function case is more fundamental; the non-arrow case could be
  hacked together somehow if we implemented tracking is_simple for each param
  separately; but now that it's possible to bail out consistently from both
  cases, I don't think the is_simple complication is worth it.

- The added mjsunit test cases are based on the test262 test cases which exposed
  the problem.

- cctest/preparser/PreParserScopeAnalysis was exercising similar cases, but the
  problem didn't show up because the function parameters didn't contain
  skippable functions. Those test cases have been repurposed for testing the
  bailout.

- Extra precaution: the bailout tests are in a separate file, to guard from the
  bug that a bailout case results in bailing out of *all* data creation, which
  would make all skipping tests in the same file useless.

BUG=v8:5516

Change-Id: I4324749a5ec602fa5d7dc27647ade0284a6842fe
Reviewed-on: https://chromium-review.googlesource.com/599849Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47170}