Previously we had passed kOnEntryBreakpointPosition as a marker through
the regular SetBreakPointForScript() logic and handled that specially in
WasmScript, however this instrumentation breakpoint is special and gets
in the way of returning more information about a regular breakpoint in
case of crbug.com/700516, so I decided to just isolate that into it's
own method, especially since the only user already special-cases Wasm
anyways.

Bug: chromium:1162229, chromium:700516
Change-Id: Ie7966c1701365a4b03710d6dc32cc8278577ee3a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3026711
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75724}