port 5dff4bdf (r29886).

original commit message:

    No need to pass the name explicitly to the stubs; the runtime can
    extract the name from the ScopeInfo (the extension of the
    ScriptContext) on-demand easily without any performance impact.

BUG=

Review URL: https://codereview.chromium.org/1259063004

Cr-Commit-Position: refs/heads/master@{#29892}