JSFunction::SetName can fail if it tries to create a string with
length > String::kMaxLength (either by prepending "set "/"get " or
by surrounding a Symbol descriptor with "["/"]").

This patch propagates that exception to the surrounding code rather
than CHECK-failing.

Bug: chromium:740398
Change-Id: I394943af481f3147387dd82ec5862d7071d57827
Reviewed-on: https://chromium-review.googlesource.com/566092Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46601}