Normative change in ecma262 [1].

Errors thrown by GetMethod(iterator, "return") are suppressed in favor
of the original exception.

[1] https://github.com/tc39/ecma262/pull/1408

Bug: v8:10397
Change-Id: I0dea8bd677c557cced7103c846416bd81f06f482
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2183400
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67662}