As part of the effort to despecialize WASM code, convert many uses of
WasmInstanceObject which were simply indirecting through to either
the compiled module or the shared module data with helpers on
the respective Frame objects.

R=mstarzinger@chromium.org

Bug: 
Change-Id: I05bd1a18b1d81cceef8a80d9f6988e4f5d537e66
Reviewed-on: https://chromium-review.googlesource.com/876125
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50798}