cmd/compile/internal/noder: preserve alias uses in export data
This CL changes the export data format to preserve alias uses.
Previously they were stripped away with types2.Unalias. For backwards
compatibility, we use pkgbits.TypeNamed, which is already used for the
predeclared aliases byte, rune, and any.
While here, remove unnecessary uses of types2.Unalias, and add a
missing one in recvBase to handle:
type T int
type A = T
func (*A) m() {}
Change-Id: I62ddb0426080a44436054964a90ab250bcd8df12
Reviewed-on: https://go-review.googlesource.com/c/go/+/558577 Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>