So far, calls to Wasm C/C++ API functions reused the call descriptors
of WasmImportWrappers, and the stack frame type of regular Wasm
functions. This CL cleans that up by introducing separate implementations
for both. No change in functionality or performance is expected.

Change-Id: I79301fa81da52283cc776ddf19d4712372f3a58b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1632235
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61914}