Following CL 405114, the extension rule is also wrong. It is safe
to drop the extension if the value is from a boolean-generating
instruction, but not a boolean-typed Value in general (e.g. a Phi
or a in-register parameter). Fix it.
Updates #52788.
Change-Id: Icf3028fe8e90806f9f57fbe2b38d47da27a97e2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/405115
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
