Delegate throwing in RegExpExecStub to CEntryStub.

Delegate throwing in RegExpExecStub to CEntryStub.

This ensures that there is only one stub that deals with unwinding the
stack. Having more than one place containing that logic is brittle and
error prone, especially when it is a corner case only for RangeErrors.

R=titzer@chromium.org
TEST=mjsunit/regress/regress-crbug-467047
BUG=chromium:467047
LOG=N

Review URL: https://codereview.chromium.org/1012103002

Cr-Commit-Position: refs/heads/master@{#27243}