- Implemented ops: I32AtomicAnd, I32AtomicAnd8U, I32AtomicAnd16U, I32AtomicOr,
 I32AtomicOr8U, I32AtomicOr16U, I32AtomicXor, I32AtomicXor8U, I32AtomicXor16U
 - Refactor wasm-compiler AtomicOp to use macros
 - Tests

Bug:V8:6532

R=binji@chromium.org, bbudge@chromium.org, bradnelson@chromium.org

Change-Id: I7e4dc8ad8cf3e211c3aef721a02778f2a4621322
Reviewed-on: https://chromium-review.googlesource.com/600539Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47172}