Some helpers that depend on a MachineGraph or WasmGraphAssembler are
moved into WasmGraphAssembler. Also, GetAsmJsOOBValue is inlined.

Change-Id: I8760218cdba1e0f1564cdb044def4a68b348eac3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2717303Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73014}