MIPS: * src/generator.js: Add methods and intialization for generator meta-objects.

MIPS: * src/generator.js: Add methods and intialization for generator meta-objects.

Port r14236 (7d56d7c5)

Original commit message:
* src/generator.js: Add methods and intialization for generator meta-objects.

* src/contexts.h:
* src/bootstrapper.cc (InitializeExperimentalGlobal): Make generator
  meta-objects, and store maps for constructing generator functions
  and their prototypes.

* src/factory.h:
* src/factory.cc (MapForNewFunction): New helper.
  (NewFunctionFromSharedFunctionInfo): Use the new helper.

* src/heap.cc (AllocateFunctionPrototype, AllocateInitialMap): For
   generators, allocate appropriate prototypes and maps.

* src/code-stubs.h:
* src/arm/code-stubs-arm.h:
* src/arm/full-codegen-arm.h:
* src/ia32/code-stubs-ia32.h:
* src/ia32/full-codegen-ia32.h:
* src/x64/code-stubs-x64.h:
* src/x64/full-codegen-x64.h: Allow fast closure creation for generators,
using the appropriate map.

* test/mjsunit/harmony/builtins.js: Add a special case for
  GeneratorFunctionPrototype.prototype.__proto__.

BUG=

Committed: https://code.google.com/p/v8/source/detail?r=14238

[Paul Lind, 2013-04-11 23:11:09]

lgtm

[palfia, 2013-04-11 23:25:21]

Committed manually as r14238 (presubmit successful).