This reverts commit d5565c1f.

Getter and setter function names in ES6 are defined as "get foo" and
"set foo".

This also moves the logic for handling symbols from runtime-function.cc
to v8natives.js.

BUG=None
LOG=N
R=adamk@chromium.org

Review URL: https://codereview.chromium.org/1093183006

Cr-Commit-Position: refs/heads/master@{#28050}