[SIMD] Fix d8 crashes when constructing simd128 typed array without simd flag

The simd128 typed array constructors should be guarded by simd-object
runtime flag.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1250
Merge pull request #11 from huningxin/fix_x4_typed_array

[SIMD] Fix d8 crashes when constructing x4 typed array without --simd-ob...