go/types, types2: more concise error if conversion fails due to integer overflow

go/types, types2: more concise error if conversion fails due to integer overflow

This change brings the error message for this case back in line
with the pre-Go1.18 error message.

Fixes #63563.

Change-Id: I3c6587d420907b34ee8a5f295ecb231e9f008380
Reviewed-on: https://go-review.googlesource.com/c/go/+/538058
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Bypass: Robert Griesemer <gri@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>