Make key in for-in not typable.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=57017457
Don't crash on hook that contains function expressions.

Fixes issue 1147.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=57019967