SIMD type conversion for x86

Rationale:
Break-out CL of ART Vectorizer: 1 OF many
Needed to demonstrate that same-length
type conversions easily fit the model.

Bug: 34083438
Test: assembler_x86[_64]_test
Change-Id: Ib9959a7e18485ab1629978c61032fcda16792951
6 files changed