go/types, types2: don't print aliased type (in comments) for Alias types

Fixes #64584.

Change-Id: I756d6026d10f130c1dd5026891b7cc3c640d7f78
Reviewed-on: https://go-review.googlesource.com/c/go/+/548135
Reviewed-by: Alan Donovan <[email protected]>
Run-TryBot: Robert Griesemer <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Robert Griesemer <[email protected]>
Auto-Submit: Robert Griesemer <[email protected]>

Author: griesemer

src/cmd/compile/internal/types2/issues_test.go

@@ -998,7 +998,7 @@ type S struct{ A }
 	}
 
 	got := S.String()
-	const want = "type p.S struct{p.A /* = []int */}"
+	const want = "type p.S struct{p.A}"
 	if got != want {
 		t.Fatalf("got %q; want %q", got, want)
 	}

src/cmd/compile/internal/types2/typestring.go

@@ -331,8 +331,6 @@ func (w *typeWriter) typ(typ Type) {
 		if w.ctxt != nil {
 			// TODO(gri) do we need to print the alias type name, too?
 			w.typ(Unalias(t.obj.typ))
-		} else {
-			w.string(fmt.Sprintf(" /* = %s */", Unalias(t.obj.typ)))
 		}
 
 	default:

src/go/types/issues_test.go

@@ -1008,7 +1008,7 @@ type S struct{ A }
 	}
 
 	got := S.String()
-	const want = "type p.S struct{p.A /* = []int */}"
+	const want = "type p.S struct{p.A}"
 	if got != want {
 		t.Fatalf("got %q; want %q", got, want)
 	}

src/go/types/typestring.go

@@ -334,8 +334,6 @@ func (w *typeWriter) typ(typ Type) {
 		if w.ctxt != nil {
 			// TODO(gri) do we need to print the alias type name, too?
 			w.typ(Unalias(t.obj.typ))
-		} else {
-			w.string(fmt.Sprintf(" /* = %s */", Unalias(t.obj.typ)))
 		}
 
 	default: