DEPS.xwalk: Roll v8-crosswalk (8baa2b8 -> 402ca0b).

* 402ca0b Merge pull request #44 from huningxin/simd-jsobject
* 0fe7e99 Inline the simd128-tag
* af33544 Fix the presubmit step
* 97783aa Inline all SIMD operations and optimize the SIMD arrays load and store.
* adeeda9 Change Float32x4, Float64x2 and Int32x4 to JSObject.
* a89309d Introduce Float32x4, Float64x2, Int32x4, Float32x4Array, Float64x2Array and Int32x4Array data types, implement the SIMD operations on the Float32x4, Float64x2 and Int32x4 with C++ runtime functions and implement Float32x4Array, Float64x2Array and Int32x4Array element loading and storing.

BUG=XWALK-2185