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>
1 file changed