tree a8b7fb206d30b0a9857ab1c845e692db4c240f04
parent f92a3589fa04285dccab3ca7454eaaf2d0e7cde3
author Robert Griesemer <gri@golang.org> 1634594168 -0700
committer Robert Griesemer <gri@golang.org> 1634662895 +0000

cmd/compile, types2: better error message for invalid type assertion

This CL addresses the 2nd part of the issue below.

- For types2, now use the same error messages as the compiler in this case.
- Make the mechanism for reporting clarifying error messages handle the case
  where we don't have additional position information.
- Provide context information (type assertion vs type switch).

Fixes #49005.

Change-Id: I4eeaf4f0c3f2f8735b63993778f58d713fef21ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/356512
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Robert Findley <rfindley@google.com>