Bug 843462 (part 1) - Make Vector::insert() less error-prone.  r=luke.

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extra : rebase_source : 8cc2ba2a01d7d4970aacb7728bb2936ea473dcf5
Bug 843462 (part 2) - Use a Vector to build the source notes.  r=jorendorff.

--HG--
extra : rebase_source : 57d50732d55b9e73bad04ec0c01b58b20de275b3
Bug 843462 (part 3) - Use a Vector to build the bytecode.  r=jorendorff.

--HG--
extra : rebase_source : b5f266d41f94daf626540f40986f22a1f26c0556