port 46648402 https://crrev.com/c/1871605

Original Commit Message:

CallDebugOnFunctionCall was always using Registers and not Immediates.
    Then ParameterCount is not really needed. Since updating that, we
    could update other functions, e.g InvokeFunction, to only use
    registers too.

    Also removed now irrelevant variables, e.g definitely_mismatches.

[mips][codegen] Removed ParameterCount class

port 1e696896 https://crrev.com/c/1886916

Original Commit Message:

    It was used only with Register inputs, so we can replace its uses with
    the Registers themselves.

Change-Id: I0a661519f5602bf4d52c40c6c238436b93b71664
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1898826Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64753}