- Reworks the code structure to break out 3 major cases:
  Immediate, MemoryOperand, and LocationOperand.
- InstructionSelector passes an additional immediate operand,
  the push size in bytes, so we can generate correct code
  for the Immediate case.

Bug: v8:9198

Change-Id: I86cd41826150aa84b158fdbb1d3e8f3e93755119
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2673273
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72553}