- Supports Float64 Add for SmiAdd bytecode
- Adds a Float64Constant and ChangeInt32ToFloat64 nodes
- Converts floats to tagged in Phi node inputs
- Fixes spill double representation
- Fixes materialisation during a deopt of a double in the stack

Bug: v8:7700
Change-Id: I9217a64313b4bd5d0015f935c23771ecf9a2c7ca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3610426
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80255}