We do not need to go through the builtin when the function reference is
already set.
For faster checks, we ensure that
{WasmInstanceObject::wasm_internal_functions} is set at instance
object instantiation time. Therefore it does not need to be optional.
Change-Id: Ie0a6564c171c6a6e3424c3cc0eeae3c83929e616
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4005823
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#84095}