Bug 1032726 part 2 - Make GetArrayIndexFromId work with Latin1 strings. r=bz,terrence

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extra : rebase_source : b6f8fe3df3946dfe05f5467c22c4fb157b6dcbf2
Bug 1032726 part 3 - Make FindEnumStringIndex work with Latin1 strings. r=bz,terrence

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extra : rebase_source : dd266d1453f926438eec533502d75e2a7de37795