This CL adds support for instrumentation breakpoints in wasm. The
request for "break on entry" is set on the script, and we need to keep
it stored there because there might not be any instances of that wasm
module yet. Once instances get created, the flag value is transferred to
all instances. The flag stored there is then checked in the function
prologue in Liftoff debugging code. This ensures that we will stop at
the first valid break position in any function within that module.
Hitting that instrumentation breakpoint will then clear the flag from
the script and from all other live instances (in the same isolate).

A first basic test is contained in this CL. More tests will be added
later.

R=thibaudm@chromium.org, bmeurer@chromium.org

Bug: chromium:1151211
Change-Id: I5442d4044934988269becececc03699b850d51d7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2690588Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72701}