go/types, types2: more concise error messages for cycle errors
If a cycle has length 1, don't enumerate the single cycle entry;
instead just mention "refers to itself". For instance, for an
invalid recursive type T we now report:
invalid recursive type: T refers to itself
instead of:
invalid recursive type T
T refers to
T
Adjust tests to check for the different error messages.
Change-Id: I5bd46f62fac0cf167f0d0c9a55f952981d294ff4
Reviewed-on: https://go-review.googlesource.com/c/go/+/436295
Run-TryBot: Robert Griesemer <gri@google.com> Reviewed-by: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Robert Griesemer <gri@google.com>