Thrown exceptions must be handled before another exception is thrown.
This fixes all remaining test failures exposed by not clearing pending
exceptions in JSEntryStub.

BUG=v8:5259

Review-Url: https://codereview.chromium.org/2207923002
Cr-Commit-Position: refs/heads/master@{#38324}

Flags removed (all begin with "harmony-"):
  function-name
  instanceof
  iterator-close
  unicode-regexps
  regexp-exec
  regexp-subclass
  species

BUG=v8:3566, v8:3648, v8:3699, v8:4093, v8:4447, v8:4602

Review-Url: https://codereview.chromium.org/2096933002
Cr-Commit-Position: refs/heads/master@{#37235}

R=aizatsky@chromium.org, jochen@chromium.org, kcc@chromium.org, ochang@chromium.org
BUG=584819
LOG=Y

Review-Url: https://codereview.chromium.org/1927933002
Cr-Commit-Position: refs/heads/master@{#35866}

BUG=chromium:577261
R=machenbach@chromium.org,yangguo@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/1652963002

Cr-Commit-Position: refs/heads/master@{#33673}

R=jochen@chromium.org, machenbach@chromium.org
BUG=chromium:577261
LOG=N

Review URL: https://codereview.chromium.org/1660463002

Cr-Commit-Position: refs/heads/master@{#33661}

R=jochen@chromium.org
BUG=chromium:577261
LOG=N

Review URL: https://codereview.chromium.org/1655853002

Cr-Commit-Position: refs/heads/master@{#33640}