[wasm] Fix ToNumber conversion

[wasm] Fix ToNumber conversion

There were two bugs, one partly hiding the other one:
1) We generate the ToNumber conversion for each WASM_TO_JS wrapper,
   even if the expected return type is void.
2) The return node in the WASM_TO_JS wrapper did not use the effect of
   the ToNumber conversion.

This CL fixes both, and adds test cases to check that we do throw an
error trying to convert (e.g.) Symbol to a number, but only if the
return type is not void.
Additional test check that a user-provided valueOf method is actually
called the correct number of times.

R=titzer@chromium.org, bradnelson@chromium.org
BUG=v8:4203
Committed: https://crrev.com/ae1c5746f26d19573666790e8a98e1a80ef62562
Cr-Commit-Position: refs/heads/master@{#41552}

[Clemens Hammacher, 2016-12-07 11:08:38]

The CQ bit was checked by clemensh@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-07 11:08:48]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Clemens Hammacher, 2016-12-07 11:18:31]

The CQ bit was checked by clemensh@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-07 11:18:38]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[bradnelson, 2016-12-07 11:21:51]

lgtm

[commit-bot: I haz the power, 2016-12-07 11:42:54]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-07 11:42:54]

Dry run: This issue passed the CQ dry run.

[titzer, 2016-12-07 13:49:27]

On 2016/12/07 11:21:51, bradnelson wrote:
> lgtm

lgtm

[Clemens Hammacher, 2016-12-07 13:51:23]

The CQ bit was checked by clemensh@chromium.org

[commit-bot: I haz the power, 2016-12-07 13:51:29]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-07 13:54:03]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1481118683416850,
"parent_rev": "20f643b53eb99891bef77f6033495d1e52732943", "commit_rev":
"d41d7212f7e4cbc0a6a355af5579508ee04c97cd"}

[commit-bot: I haz the power, 2016-12-07 13:54:06]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-12-07 13:54:32]

Description was changed from

==========
[wasm] Fix ToNumber conversion

There were two bugs, one partly hiding the other one:
1) We generate the ToNumber conversion for each WASM_TO_JS wrapper,
   even if the expected return type is void.
2) The return node in the WASM_TO_JS wrapper did not use the effect of
   the ToNumber conversion.

This CL fixes both, and adds test cases to check that we do throw an
error trying to convert (e.g.) Symbol to a number, but only if the
return type is not void.
Additional test check that a user-provided valueOf method is actually
called the correct number of times.

R=titzer@chromium.org, bradnelson@chromium.org
BUG=v8:4203
==========

to

==========
[wasm] Fix ToNumber conversion

There were two bugs, one partly hiding the other one:
1) We generate the ToNumber conversion for each WASM_TO_JS wrapper,
   even if the expected return type is void.
2) The return node in the WASM_TO_JS wrapper did not use the effect of
   the ToNumber conversion.

This CL fixes both, and adds test cases to check that we do throw an
error trying to convert (e.g.) Symbol to a number, but only if the
return type is not void.
Additional test check that a user-provided valueOf method is actually
called the correct number of times.

R=titzer@chromium.org, bradnelson@chromium.org
BUG=v8:4203

Committed: https://crrev.com/ae1c5746f26d19573666790e8a98e1a80ef62562
Cr-Commit-Position: refs/heads/master@{#41552}
==========

[commit-bot: I haz the power, 2016-12-07 13:54:33]

Patchset 2 (id:??) landed as
https://crrev.com/ae1c5746f26d19573666790e8a98e1a80ef62562
Cr-Commit-Position: refs/heads/master@{#41552}