go/types, types2: slightly simplify rangeKeyVal function
Compute the signature type of an iterator function argument
only once. This eliminates the need for two separate toSig
calls.
Change-Id: Ifeb33d21e381010d2012d74eac045856f1cca312
Reviewed-on: https://go-review.googlesource.com/c/go/+/613635
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com> Reviewed-by: Tim King <taking@google.com>