Bug 1093573 part 1 - Some generator bytecode changes. r=wingo

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extra : rebase_source : d5d35bc7f367f3a3427bf22a8bdd83b1ea76be16
Bug 1093573 part 2 - Remove GENERATOR frame flag. r=wingo

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extra : rebase_source : 51bc843a9bf27c3e3a6718867d6e7953970b9787
Bug 1093573 part 3 - Use AbstractFramePtr in GeneratorObject methods. r=wingo

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extra : rebase_source : a2a1b2276a3ba52414fd7f72d767cbf07565e686