Merge pull request #308 from bocoup/for-of-built-ins

test/language/statements/for-of/arguments-mapped-aliasing.js

test/language/statements/for-of/arguments-mapped-mutation.js

test/language/statements/for-of/arguments-mapped.js

...language/statements/for-of/arguments-unmapped-aliasing.js

...language/statements/for-of/arguments-unmapped-mutation.js

test/language/statements/for-of/arguments-unmapped.js

test/language/statements/for-of/array-contract-expand.js

test/language/statements/for-of/array-contract.js

test/language/statements/for-of/array-expand-contract.js

test/language/statements/for-of/array-expand.js

test/language/statements/for-of/array-key-get-error.js

test/language/statements/for-of/float32array-mutate.js

test/language/statements/for-of/float32array.js

test/language/statements/for-of/float64array-mutate.js

test/language/statements/for-of/float64array.js

test/language/statements/for-of/int16array-mutate.js

test/language/statements/for-of/int16array.js

test/language/statements/for-of/int32array-mutate.js

test/language/statements/for-of/int32array.js

test/language/statements/for-of/int8array-mutate.js