recover determines whether it's being called by a deferred frame by
matching its caller's argument frame pointer with the one recorded in
the panic object. That means its caller needs a valid and unique
argument frame pointer, so it must not be inlined.

With this fix, test/recover.go passes with -l=4.

Fixes #23557.

Change-Id: I1f32a624c49e387cfc67893a0829bb248d69c3d4
Reviewed-on: https://go-review.googlesource.com/90035
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>