- Renames Create ops to Splat.
- Adds machine operators to initialize all SIMD machine types.
  Boolean vector types may need initialization, so provide zero
  operators.

LOG=N
BUG=v8:4124,695330

Review-Url: https://codereview.chromium.org/2719483002
Cr-Commit-Position: refs/heads/master@{#43430}