Add tests for `for..of` iteration over built-ins

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

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

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

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

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

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

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