Record field initializer stores with simple literals at compile-time.

Record field initializer with simple literals stores at compile-time.

This helps to rule out fields from being unboxing candidates earlier and
avoids generating extra code to track the type at runtime.

Also, align the location summary computation for instance field stores to
use the same condition as the code generation function.

R=vegorov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=37310

[Florian Schneider, 2014-06-13 11:10:40]

When running dart2js, this avoid generating ~100 potential-unboxed stores,
therefore reducing the size of unoptimized code.

[Vyacheslav Egorov (Google), 2014-06-13 11:17:11]

LGTM

though I am a bit concerned that this only covers 

var x = literal; 

case 

better solution would be to have a slow path stub for a potentially unboxed
stores in the unoptimized code.

[Florian Schneider, 2014-06-13 11:19:20]

On 2014/06/13 11:17:11, Vyacheslav Egorov (Google) wrote:
> LGTM
> 
> though I am a bit concerned that this only covers 
> 
> var x = literal; 
> 
> case 
> 
> better solution would be to have a slow path stub for a potentially unboxed
> stores in the unoptimized code.

Yes, we still want the stub in unoptimized code. This is merely ruling out cases
that are
obvious.

[Florian Schneider, 2014-06-13 11:49:41]

Committed patchset #1 manually as r37310 (presubmit successful).