Fix invalid native context reference in simd128-tag

The solution is to inline the native context load.

BUG=XWALK-2255
Temporarily disable Distributivity1 test in M37 to pass x64 trybot

TODO(ningxin): look at this case in M38.
Merge pull request #46 from huningxin/fix-context-load

Fix invalid native context reference in simd128-tag