Bug 869730 - Fix an opt build error with --enable-gcgenerational; r=billm

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extra : rebase_source : e03f499f82186b84226026fc6856399ae511849d
Bug 869235 - Disable Zone::needsBarrier during minor GCs; r=billm

--HG--
extra : rebase_source : be141178dc9cf2da06d9eb2f13189f1db0876433
Bug 869742 - Add post-barriers for writes to liveScopes; r=billm

--HG--
extra : rebase_source : 37596559db5d11f160f2c220a27effd575c9b508
Bug 869735 - Fixes to ParallelArray compilation to support generational GC; r=nmatsakis

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extra : rebase_source : 41b4380630b0f47326a707a15b597ce22bb24caa
Fix warnings-as-errors bustage from changeset 09552b219c3a (Bug 828312 patch 3).