When v8_enable_embedded_bytecode_handlers is true, initialize the
bytecode dispatch table from the builtins table. Also stops creating
the handlers more than once as the SetupInterpreter will now always do
nothing even when not starting from a snapshot.

In the short term, with the flag enabled all the bytecode handlers are
eagerly deserialized.

Finally, the bytecode handlers are marked as non-isolate independent to
prevent them being embedded in the binary until they can be converted.

Bug: v8:8068
Change-Id: I9e5ef7f1dce1b2d11c7aa26526f06b53f8939697
Reviewed-on: https://chromium-review.googlesource.com/1188477Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55581}