When running without a snapshot, the GlobalEval function gets lazy compiled.
By the time we compile it, its name is "eval", which causes the parser to
choke (functions named "eval" aren't allowed in strict mode!).

Instead, we now always skip checking the function name when lazy-parsing,
as the name has already been checked appropriately by the preparser.

Also cleaned up other cases that don't require name checking by introducing
FunctionNameValidity enum and passing appropriate values throughout the
parser and preparser.

This lets us pass an additional 18 test262 tests.

BUG=v8:4198
LOG=n

Review URL: https://codereview.chromium.org/1227093005

Cr-Commit-Position: refs/heads/master@{#29559}