First step towards the new exception handling proposal:
https://github.com/WebAssembly/exception-handling/issues/125

This is essentially a revert of:
"[wasm] Switch to new 'catch' and 'br_on_exn' proposal."

The changes are:
- "catch" instruction takes a tag immediate,
- "rethrow" instruction takes a label immediate,
- Add "catch_all" instruction,
- Remove "br_on_exn" instruction,
- Do not push exceptions on the stack, only the encoded values

R=clemensb@chromium.org
CC=​aheejin@chromium.org

Bug: v8:8091
Change-Id: Iea4d8d5a5d3ad50693f645e93c13e8de117aa884
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484514
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71602}