go/types: add check that code is monomorphizable

go/types: add check that code is monomorphizable

This CL adds a check to ensure that generic Go code doesn't involve
any unbounded recursive instantiation, which are incompatible with an
implementation that uses static instantiation (i.e., monomorphization
or compile-time dictionary construction).

Updates #48098.

Change-Id: I9d051f0f9369ab881592a361a5d0e2a716788a6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/357449
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>