Resolve references to "this" the same way as normal variables

Resolve references to "this" the same way as normal variables

Make the parser handle references to "this" as unresolved variables, so the
same logic as for the rest of function parameters is used for the receiver.
Minor additions to the code generation handle copying the receiver to the
context, along with the rest of the function parameters.

Based on work by Adrian Perez de Castro <aperez@igalia.com>;.

BUG=v8:2700
LOG=N

Committed: https://crrev.com/06a792b7cc2db33ffce7244c044a9c05afbb6116
Cr-Commit-Position: refs/heads/master@{#28263}

[wingo, 2015-05-06 13:13:34]

wingo@igalia.com changed reviewers:
+ arv@chromium.org, rossberg@chromium.org

[wingo, 2015-05-06 13:13:34]

This is a reapplication of https://codereview.chromium.org/1097283003.  The
first patch is just the rebased original patch.  The second version adds the
nosnap test fix, along with mips/mips64 backend support.

[rossberg, 2015-05-06 13:17:05]

lgtm

[wingo, 2015-05-06 13:34:30]

The CQ bit was checked by wingo@igalia.com

[commit-bot: I haz the power, 2015-05-06 13:34:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1130733003/20001

[commit-bot: I haz the power, 2015-05-06 14:18:10]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-06 14:18:23]

Patchset 2 (id:??) landed as
https://crrev.com/06a792b7cc2db33ffce7244c044a9c05afbb6116
Cr-Commit-Position: refs/heads/master@{#28263}

[Michael Achenbach, 2015-05-07 07:20:13]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1129723003/ by machenbach@chromium.org.

The reason for reverting is: [Sheriff] Breaks jetstream benchmark with errors
like this:

>>> Running suite: JetStream/bigfib.cpp
>>> Stdout (#1):
undefined:93: ReferenceError: this is not defined
  this['Module'] = Module;
  ^
ReferenceError: this is not defined
    at eval (eval at __run (runner.js:13:3), <anonymous>:93:3)
    at eval (native)
    at __run (runner.js:13:3)
    at Object.runSimpleBenchmark (runner.js:44:31)
    at runner.js:97:13.