cmd/compile/internal/types2: use go/types/testdata/examples tests
Since the examples tests are now identical between the two type checkers,
remove the local copy of the examples tests and (for now) use the tests
in go/types/testdata/examples instead. Eventually we may decide to move
all tests out of the type checker directories and place them in a
shared space (e.g. internal/types/testdata).
For #54511.
Change-Id: Ibd8599d09e781b2219a23114b4b2049757971181
Reviewed-on: https://go-review.googlesource.com/c/go/+/424695 Reviewed-by: Robert Findley <rfindley@google.com> Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>