This CL adds
- CodeT type - an alias for CodeDataContainer or Code depending on
  whether the v8_enable_external_code_space is enabled or not,
- a set of conversion functions from CodeT to Code or CodeDataContainer
  and back (both in C++ and CodeStubAssembler),
- masm support for calling/tailcalling via CallDataContainer which
  contain the code entry point address,
- masm support for calling/tailcalling via CodeT.

Bug: v8:11880
Change-Id: Ib36f4c6db69ec49aaea29412647e59ada95da19b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2967463
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75207}