This CL adds a --debug-in-liftoff flag, which takes another path in
{WasmScript::SetBreakPointForFunction}, and sets the breakpoint via
{wasm::DebugInfo} (Liftoff-related) instead of {WasmDebugInfo} (C++
interpreter related).
Actual breakpoint support is not there yet, so the new test which sets
this flag does not currently break anywhere. This will change with a
future CL.

R=thibaudm@chromium.org

Bug: v8:10147
Change-Id: I95a905e666b8f502366d2c7273c8f25a267ee184
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2012920
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65921}