Implements the strong mode proposal's static restrictions on the use of the
identifier 'undefined', for arrow functions. Assumes these restrictions are
intended to be identical to the restrictions on the use of 'eval and 'arguments'
in strict mode. In addition, Location variables inconsistantly named (e.g.
dupe_error_loc vs dupe_loc) are now consistently named the shorter way.
Baseline: https://codereview.chromium.org/1070633002
BUG=v8:3956
LOG=N
Review URL: https://codereview.chromium.org/1060883004
Cr-Commit-Position: refs/heads/master@{#27756}
3d5717a71b