This makes WebAssembly runtime stubs use Smi encoding for parameters in
instead of a HeapNumber encoding whenever possible. This potentially
avoids allocating on the GC'ed heap.

R=clemensb@chromium.org

Change-Id: Ie37c3005442748d9bd71da59a2c11d103a65fe9c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1895574
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64745}