cmd/compile: output cost while inlining function with Debug['m'] > 1
The existing implementation outputs inline cost iff function cannot be inlined with Debug['m'] > 1, the cost info is also useful if the function is inlineable.
Fixes #36780
Change-Id: Ic96f6baf96aee25fb4b33d31d4d644dc2310e536
Reviewed-on: https://go-review.googlesource.com/c/go/+/216778
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>