Hydrogenized KeyedLoadGeneric stub: Fix BuildDecodeField

Hydrogenized KeyedLoadGeneric stub: Fix BuildDecodeField

R=yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=22185

[Jakob Kummerow, 2014-07-03 08:46:25]

PTAL.

For reference, the C++ implementation is:

static T decode(U value) {
  return static_cast<T>((value & kMask) >> shift);
}

[Yang, 2014-07-03 08:47:34]

On 2014/07/03 08:46:25, Jakob wrote:
> PTAL.
> 
> For reference, the C++ implementation is:
> 
> static T decode(U value) {
>   return static_cast<T>((value & kMask) >> shift);
> }

lgtm.

[Jakob Kummerow, 2014-07-03 08:58:13]

Committed patchset #1 manually as r22185 (presubmit successful).