Allow embedding of ConsString objects into code.

Allow embedding of ConsString objects into code.

R=yangguo@chromium.org
BUG=v8:2803
LOG=N

Committed: https://code.google.com/p/v8/source/detail?r=22406

[Michael Starzinger, 2014-07-15 07:47:59]

By now this seems to be a matter of removing asserts. Please note that this
change still doesn't do short-circuiting of embedded ConsString objects in code.
This can be done in a follow-up CL if necessary by adapting
VisitEmbeddedPointer.

[Yang, 2014-07-15 08:09:13]

On 2014/07/15 07:47:59, Michael Starzinger wrote:
> By now this seems to be a matter of removing asserts. Please note that this
> change still doesn't do short-circuiting of embedded ConsString objects in
code.
> This can be done in a follow-up CL if necessary by adapting
> VisitEmbeddedPointer.

LGTM. You may want to look at HStringAdd::New and the call to
Factory::NewFlatConcatString. The reason we use that instead of
Factory::NewConsString is this as well, iirc.

[Michael Starzinger, 2014-07-15 09:40:00]

On 2014/07/15 08:09:13, Yang wrote:
> On 2014/07/15 07:47:59, Michael Starzinger wrote:
> > By now this seems to be a matter of removing asserts. Please note that this
> > change still doesn't do short-circuiting of embedded ConsString objects in
> code.
> > This can be done in a follow-up CL if necessary by adapting
> > VisitEmbeddedPointer.
> 
> LGTM. You may want to look at HStringAdd::New and the call to
> Factory::NewFlatConcatString. The reason we use that instead of
> Factory::NewConsString is this as well, iirc.

Done.

[Yang, 2014-07-15 09:49:07]

lgtm.

https://codereview.chromium.org/395713002/diff/40001/src/hydrogen-instruction...
File src/hydrogen-instructions.cc (right):

https://codereview.chromium.org/395713002/diff/40001/src/hydrogen-instruction...
src/hydrogen-instructions.cc:4072: ASSERT(!concat.is_null());
This assertion is obsolete since we do a ToHandleChecked().

[Michael Starzinger, 2014-07-15 09:52:47]

Addressed comments. Thanks. Landing.

https://codereview.chromium.org/395713002/diff/40001/src/hydrogen-instruction...
File src/hydrogen-instructions.cc (right):

https://codereview.chromium.org/395713002/diff/40001/src/hydrogen-instruction...
src/hydrogen-instructions.cc:4072: ASSERT(!concat.is_null());
On 2014/07/15 09:49:06, Yang wrote:
> This assertion is obsolete since we do a ToHandleChecked().

Done.

[Michael Starzinger, 2014-07-15 10:51:28]

Committed patchset #3 manually as r22406 (presubmit successful).