Intrinsify ExternalUint8Array.[].

Intrinsify ExternalUint8Array.[].

This helps the HTTP parser quite a bit. I was playing around with
it and thought I might as well upload it for review. Feel free
to take over the changelist if I'm doing this wrong. In that
case you should see this as a request for intrinsification of
ExternalUint8Arrays. :-)

R=fschneider@google.com,srdjan@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=15200

[Florian Schneider, 2012-11-21 15:15:17]

LGTM.

Of course, we also want an IL instruction in the optimizing compiler eventually.

https://codereview.chromium.org/11280121/diff/1/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/11280121/diff/1/runtime/vm/object.h#newcode5161
runtime/vm/object.h:5161: return length_offset() + kWordSize;
Maybe instead use OFFSET_OF here as well?

https://codereview.chromium.org/11280121/diff/1/runtime/vm/raw_object.h
File runtime/vm/raw_object.h (right):

https://codereview.chromium.org/11280121/diff/1/runtime/vm/raw_object.h#newco...
runtime/vm/raw_object.h:1368: return 0;
I think 

OFFSET_OF(ExternalByteArrayData<T>, data_)

should work.

[Mads Ager (google), 2012-11-21 15:31:34]

Thanks Florian. I change all of the data_offset getters for typed arrays to use
OFFSET_OF.

https://codereview.chromium.org/11280121/diff/1/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/11280121/diff/1/runtime/vm/object.h#newcode5161
runtime/vm/object.h:5161: return length_offset() + kWordSize;
On 2012/11/21 15:15:17, Florian Schneider wrote:
> Maybe instead use OFFSET_OF here as well?

Done for all of these.

https://codereview.chromium.org/11280121/diff/1/runtime/vm/raw_object.h
File runtime/vm/raw_object.h (right):

https://codereview.chromium.org/11280121/diff/1/runtime/vm/raw_object.h#newco...
runtime/vm/raw_object.h:1368: return 0;
On 2012/11/21 15:15:17, Florian Schneider wrote:
> I think 
> 
> OFFSET_OF(ExternalByteArrayData<T>, data_)
> 
> should work.

Done.

[srdjan, 2012-11-21 15:32:44]

What Florian wrote and LGTM