During `WasmDebugBreak` we push the full 128-bit vector register
instead of only the 64-bit FP value. As a result offset calculation
must use kSimd128Size instead of kDoubleSize.

Change-Id: Icaa44d9663024b9740acbbf054f6c334ae349cf8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3487958Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#79271}