Stepping code that is left on the stack will repeatedly call the
WasmDebugBreak function. This has no observable effect, except for
severe slowdown of execution. In the linked bug, we were executing at
least another few million instructions in the same frame, so it appeared
that it never finishes.

This CL fixes that by replacing stepping code with non-stepping code if
the WasmDebugBreak runtime function is called from stepping code but we
are not stepping (any more).
Adding a test for this is difficult, since this only has an effect on
performance.

R=thibaudm@chromium.org

Bug: chromium:1153308
Change-Id: I02feb04a156dfe81ca76ce26f0af131c470ef7a3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2775575
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73567}