Add trampoline to enable pointer -> handle code calls

Add trampoline to enable pointer -> handle code calls

R=mstarzinger@chromium.org

Committed: http://code.google.com/p/v8/source/detail?r=15507

[Michael Starzinger, 2013-07-05 07:49:07]

LGTM with comments.

https://codereview.chromium.org/18550002/diff/5001/src/factory.h
File src/factory.h (right):

https://codereview.chromium.org/18550002/diff/5001/src/factory.h#newcode572
src/factory.h:572: class IdempotentHandleToPointerCodeTrampoline {
nit: s/HandleToPointer/PointerToHandle/

https://codereview.chromium.org/18550002/diff/5001/src/factory.h#newcode579
src/factory.h:579: int scavenges = isolate_->heap()->gc_count();
nit: Since this doesn't only count minor GCs, but all GCs, let's rename this
local variable s/scavenges/collections/. Same comment applies several times
below.

https://codereview.chromium.org/18550002/diff/5001/src/factory.h#newcode589
src/factory.h:589: MaybeObject* result = (*function)();
I think the called function is not allowed to return a MaybeObject of it's own.
Handlified code has to either return Handle<T> or something that is below Object
in the type hierarchy. Can we s/MaybeObject/Object/ here? Same comment applies
several times
below.

[danno, 2013-07-05 09:35:54]

Review feedback addressed, landing

https://codereview.chromium.org/18550002/diff/5001/src/factory.h
File src/factory.h (right):

https://codereview.chromium.org/18550002/diff/5001/src/factory.h#newcode572
src/factory.h:572: class IdempotentHandleToPointerCodeTrampoline {
On 2013/07/05 07:49:07, Michael Starzinger wrote:
> nit: s/HandleToPointer/PointerToHandle/

Done.

https://codereview.chromium.org/18550002/diff/5001/src/factory.h#newcode579
src/factory.h:579: int scavenges = isolate_->heap()->gc_count();
On 2013/07/05 07:49:07, Michael Starzinger wrote:
> nit: Since this doesn't only count minor GCs, but all GCs, let's rename this
> local variable s/scavenges/collections/. Same comment applies several times
> below.

Done.

https://codereview.chromium.org/18550002/diff/5001/src/factory.h#newcode589
src/factory.h:589: MaybeObject* result = (*function)();
On 2013/07/05 07:49:07, Michael Starzinger wrote:
> I think the called function is not allowed to return a MaybeObject of it's
own.
> Handlified code has to either return Handle<T> or something that is below
Object
> in the type hierarchy. Can we s/MaybeObject/Object/ here? Same comment applies
> several times
> below.

Done.

[danno, 2013-07-05 09:36:29]

Committed patchset #4 manually as r15507 (presubmit successful).