refactor/rename: add line number to ambiguityError

Updates golang/go#19906

Change-Id: If13c828541cdb3937e5e970dd8add7615d36d866
Reviewed-on: https://go-review.googlesource.com/40171
Reviewed-by: David R. Jenni <david.r.jenni@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/refactor/rename/spec.go b/refactor/rename/spec.go
index cc1228c..c807565 100644
--- a/refactor/rename/spec.go
+++ b/refactor/rename/spec.go
@@ -558,8 +558,8 @@
 			buf.WriteString(", ")
 		}
 		posn := fset.Position(obj.Pos())
-		fmt.Fprintf(&buf, "%s at %s:%d",
-			objectKind(obj), filepath.Base(posn.Filename), posn.Column)
+		fmt.Fprintf(&buf, "%s at %s:%d:%d",
+			objectKind(obj), filepath.Base(posn.Filename), posn.Line, posn.Column)
 	}
 	return fmt.Errorf("ambiguous specifier %s matches %s",
 		objects[0].Name(), buf.String())