Bug 1081379 - change BufferKind from a bit field to a dense enum (r=sfink)

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extra : rebase_source : 19e30d746a1f4b85ae85562b5da1663bdfea2cce
Bug 1081379 - Change definition of ArrayBufferObject::hasStealableContents (r=sfink)

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extra : rebase_source : 4d0a60b7e03255317b9c880a9184fa9c07867212
Bug 1081379 - Add NIGHTLY-only ArrayBuffer.transfer (r=sfink)

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extra : rebase_source : 34d378281c18caac8a0df26938947647e6bf9529
Bug 1081379 - Optimize ArrayBuffer.transfer for 64-bit asm.js-ified ArrayBuffers (r=sfink)

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extra : rebase_source : fc2af81e096354a1c12e51b08e5886a3744a77c0