go/types, types2: add missing Unalias calls in type unifier
The unification code has "early exits" when the compared
types are pointer-identical.
Because of Alias nodes, we cannot simply compare x == y but we
must compare Unalias(x) == Unalias(y). Still, in the common case
there are no aliases, so as a minor optimization we write:
x == y || Unalias(x) == Unalias(y)
to test whether x and y are (pointer-) identical.
Add the missing Unalias calls in the place where we forgot them.
Fixes #67872.
Change-Id: Ia26ffe7205b0417fc698287a4aeb1c900d30cc0d
Reviewed-on: https://go-review.googlesource.com/c/go/+/591975 Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Robert Griesemer <gri@google.com>