CallSite depends on using the function name to get ahold of the property
name from which an exception was thrown. This fix properly handles the
ES2015 names for getters and setters. The new tests pass both with
--harmony-function-name off and on.

BUG=v8:3699
LOG=n

Review URL: https://codereview.chromium.org/1751403004

Cr-Commit-Position: refs/heads/master@{#34469}