Initialize fixed Float32x4 and Int32x4 array elements properly.

This commit should be squashed with the previous commit.
Fix shufps encoding error for x64 port

This should be squashed with previous commits.
Implement builtin operators for Float32x4 and Int32x4
Update ToBooleanStub to support Float32x4 and Int32x4
Merge pull request #19 from fenghaitao/next

Implement builtin operators for Float32x4 and Int32x4 and Update ToBooleanStub to support Float32x4 and Int32x4