Bug 933001 - Part 1/5 - Define SharedArrayBufferObject. r=sfink
Bug 933001 - Part 2/5 - Make SharedArrayBuffer usable as an AsmJS heap. r=luke
Bug 933001 - Part 3/5 - StructuredClone changes for SharedArrayBuffer. r=sfink
Bug 933001 - Part 4/5 - Add SharedArrayBuffer tests.
Bug 933001 - Part 5/5 - Pref-off SharedArrayBuffer outside Nightly. r=sfink