go/types: test shifts that are disabled in shared test file
CL 425735 consolidated the testdata/check/shifts.go files between
go/types and types2. Because some shifts don't work correctly with
types2, the corresponding tests were disabled in the shared file.
Make sure we keep testing those shifts for go/types by adding a
local test file.
For #52080.
For #54511.
Change-Id: I53507e535bf83b204eaf18fc6c2efefcebf5ebf7
Reviewed-on: https://go-review.googlesource.com/c/go/+/426661 Reviewed-by: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@google.com>