The two remaining uses of this intrinsic in debug.js and mirrors.js now
simply rely on the runtime function.

BUG=v8:5339

Review-Url: https://codereview.chromium.org/2591923003
Cr-Original-Commit-Position: refs/heads/master@{#41892}
Committed: https://chromium.googlesource.com/v8/v8/+/c9cb94a06fa7a863d24dd6760b66cecd55748abf
Review-Url: https://codereview.chromium.org/2591923003
Cr-Commit-Position: refs/heads/master@{#42128}