[builtins] Migrate Math.hypot() to C++ builtins.

[builtins] Migrate Math.hypot() to C++ builtins.

Migrate Math.hypot() from JS to C++ builtins. Use normalization and
Kahan summation to avoid overflow and rounding errors.

R=bmeurer@chromium.org
BUG=v8:5165, v8:5086
LOG=n

Committed: https://crrev.com/fe1a07fe9e6eb953418dcf2f8b751e9ca5894d42
Cr-Commit-Position: refs/heads/master@{#37473}

[Franzi, 2016-06-30 16:44:25]

Hi Benedikt, 

Here's Math.hypot() as C++ Builtin(). Please have a look. 

Thanks, 

Franzi

[Benedikt Meurer, 2016-07-01 03:41:20]

LGTM once comment is addressed. Thanks.

https://codereview.chromium.org/2102223005/diff/20001/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/2102223005/diff/20001/src/objects.h#newcode6741
src/objects.h:6741: V(Math, hypot, MathHypot)
You don't need to add it here. This is only used to recognize the function in
the optimizing compilers, but since we don't optimize it in any ways, it doesn't
have to be on this list.

[Franzi, 2016-07-01 07:47:03]

The CQ bit was checked by franzih@chromium.org

[Franzi, 2016-07-01 07:47:04]

The patchset sent to the CQ was uploaded after l-g-t-m from bmeurer@chromium.org
Link to the patchset: https://codereview.chromium.org/2102223005/#ps40001
(title: "Do not add Math.hypot() to list of optimized functions.")

[commit-bot: I haz the power, 2016-07-01 07:47:08]

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, 2016-07-01 08:13:40]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-07-01 08:15:19]

Description was changed from

==========
[builtins] Migrate Math.hypot() to C++ builtins.

Migrate Math.hypot() from JS to C++ builtins. Use normalization and
Kahan summation to avoid overflow and rounding errors.

R=bmeurer@chromium.org
BUG=v8:5165, v8:5086
LOG=n
==========

to

==========
[builtins] Migrate Math.hypot() to C++ builtins.

Migrate Math.hypot() from JS to C++ builtins. Use normalization and
Kahan summation to avoid overflow and rounding errors.

R=bmeurer@chromium.org
BUG=v8:5165, v8:5086
LOG=n

Committed: https://crrev.com/fe1a07fe9e6eb953418dcf2f8b751e9ca5894d42
Cr-Commit-Position: refs/heads/master@{#37473}
==========

[commit-bot: I haz the power, 2016-07-01 08:15:20]

Patchset 3 (id:??) landed as
https://crrev.com/fe1a07fe9e6eb953418dcf2f8b751e9ca5894d42
Cr-Commit-Position: refs/heads/master@{#37473}