This CL adds new Wasm import call kinds that correspond to various
math functions that can be imported from JavaScript, such as trigonometry.
Instead of calling a special import wrapper that converts arguments
to tagged values by boxing, we can now generate calls to little WASM
stubs that contain a single WASM bytecode each.

R=mstarzinger@chromium.org
BUG=v8:8423

Change-Id: I59b1be2dd36d190a8b6c98b88c86cecc0ca7f4a2
Reviewed-on: https://chromium-review.googlesource.com/c/1349279
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57835}