[dev.typeparams] test: add regress tests that fail(ed) with -G=3

This CL includes multiple test cases that exercise unique failures
with -G=3 mode that did not affect unified IR mode. Most of these were
found over a period of about 3 hours of manual experimentation.

Thanks to Cuong Manh Le for test cases 11 and 12.

Updates #46704.

Change-Id: Ia2fa619536732b121b6c929329065c85b9384511
Reviewed-on: https://go-review.googlesource.com/c/go/+/326169


Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>