cmd/compile/internal/inline/inlheur: rescore callsites based on result use
Add a post-processing pass that updates the scores on callsites based
on how their results are used. This is similar to the "param feeds
unmodified into <XXX>" heuristics, but applies to returned results
instead: if we know that function F always returns a constant, and we
can see that the result from a given call feeds unmodified into an
if/switch, then decrease the score on the call to encourage inlining.
Change-Id: If513765c79d868cbdf672facbff9d92ad24f909e
Reviewed-on: https://go-review.googlesource.com/c/go/+/521819 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>