This is an unmodified reland of 3c98a2a36a.
The actual issue was fixed in https://crrev.com/c/1926769.
Original change's description:
> [wasm] Prevent breakpoints on nonbreakable positions
>
> If a breakpoint is set on a non-breakable position, the wasm interpreter
> just stores the value 0xFF (kInternalBreakpoint) in the function body
> (actually, a copy of the function body). This might overwrite immediates
> and cause subsequent failures in the wasm interpreter.
>
> In JavaScript, breakpoints are just forwarded to the next breakable
> position. This CL implements the same for WebAssembly.
> A cctest tests this behavior, and the existing
> wasm-stepping-byte-offsets.js inspector test is extended to also set the
> breakpoint within an i32 constant immediate.
>
> R=leese@chromium.org, mstarzinger@chromium.org
> CC=bmeurer@chromium.org
>
> Bug: chromium:1025184
> Change-Id: Ia2706f8f1c3d686cbbe8e1e7339d9ee86247bb4a
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1925152
> Commit-Queue: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#65070}
Bug: chromium:1025184
Change-Id: I5e16df645bbacf039b7a5e55a0c2a64cdb4c6a32
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1926152
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65093}
5cf61684fb