cmd/compile/internal/types2: remove unneccesary tests in implements and lookup
Because the underlying type of a type parameter is an interface,
the questions whether *P for a type parameter P has methods or
not is settled: P is also an interface pointers to interfaces
don't have methods.
This allows us to eliminate the now unneccesary test in "implements"
and also allows us to remove a special case for type parameters in
"lookupFieldOrMethod".
Change-Id: I8b218f81584a8e42e75884089a44293365b700df
Reviewed-on: https://go-review.googlesource.com/c/go/+/363838
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Findley <rfindley@google.com>