The natives blob was deprecated in V8 7.8. This CL removes all related
functionality, including:

- Build system support, i.e.: generation of natives_blob.bin and the
v8_extra_library_files gn flag.
- Related scripts (js2c.py, concatenate-files.py).
- Related API functions (SetNativesDataBlob,
InitializeExternalStartupData).
- Natives bootstrapping logic.
- The InternalArray type (previously exposed through natives).
- Other natives-exposed builtins.
- Inlining of these builtins.
- The dedicated 'uncached external one byte string' type.

Step 1 landed in https://crrev.com/c/1824944.
Step 2 landed in https://crrev.com/c/1835536.
Step 3 (this CL) removes these all functionality related to natives
support in V8.

Bug: v8:7624
Change-Id: Ice6c2662781efe8417231805276476d32bc5a625
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1844771
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64446}