Disable dead code elimination of arguments object

Dead code elimination of inlined arguments objects causes wrong deopt info to be generated - instead of materializing the arguments, we get 'undefined'.

Golem says the change is perf-neutral.

R=mstarzinger@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=20529

[Jarin, 2014-04-07 07:45:06]

On 2014/03/25 15:27:44, jarin wrote:

ping

[Michael Starzinger, 2014-04-07 07:46:24]

LGTM.

https://codereview.chromium.org/208683006/diff/1/src/hydrogen-instructions.h
File src/hydrogen-instructions.h (right):

https://codereview.chromium.org/208683006/diff/1/src/hydrogen-instructions.h#...
src/hydrogen-instructions.h:3381: virtual bool IsDeletable() const V8_FINAL
V8_OVERRIDE { return false; }
nit: This is the default implementation in HValue, no need to override it, let's
just drop the override.

[Jarin, 2014-04-07 08:40:58]

Thanks.

https://codereview.chromium.org/208683006/diff/1/src/hydrogen-instructions.h
File src/hydrogen-instructions.h (right):

https://codereview.chromium.org/208683006/diff/1/src/hydrogen-instructions.h#...
src/hydrogen-instructions.h:3381: virtual bool IsDeletable() const V8_FINAL
V8_OVERRIDE { return false; }
On 2014/04/07 07:46:24, Michael Starzinger wrote:
> nit: This is the default implementation in HValue, no need to override it,
let's
> just drop the override.

Done.

[Jarin, 2014-04-07 08:42:44]

Committed patchset #3 manually as r20529 (presubmit successful).