The interpreter is only used for testing, and is now instantiated and
invoked directly instead of via the {WasmDebugInfo}, holding the
{InterpreterHandle}.

This CL removes both classes.

R=ahaas@chromium.org

Bug: v8:10389
Change-Id: Iede3feea413decae1edc28146b871a819e204768
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2237132Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68271}