cmd/compile/internal/types2: use go/types/testdata/check tests

Since the check tests are now identical between the two type checkers,
remove the local copy of the check tests and (for now) use the tests
in go/types/testdata/check 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: Id3a97593f6c705c5eda4566089ddc7aeb7b47337
Reviewed-on: https://go-review.googlesource.com/c/go/+/425736
Reviewed-by: Alan Donovan <adonovan@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

src/cmd/compile/internal/types2/check_test.go

@@ -297,9 +297,12 @@ func TestManual(t *testing.T) {
 
 // TODO(gri) go/types has extra TestLongConstants and TestIndexRepresentability tests
 
-func TestCheck(t *testing.T)     { DefPredeclaredTestFuncs(); testDirFiles(t, "testdata/check", 55, false) } // TODO(gri) narrow column tolerance
+func TestCheck(t *testing.T) {
+	DefPredeclaredTestFuncs()
+	testDirFiles(t, "../../../../go/types/testdata/check", 55, false) // TODO(gri) narrow column tolerance
+}
 func TestSpec(t *testing.T)      { testDirFiles(t, "../../../../go/types/testdata/spec", 0, false) }
-func TestExamples(t *testing.T)  { testDirFiles(t, "../../../../go/types/testdata/examples", 45, false) }
+func TestExamples(t *testing.T)  { testDirFiles(t, "../../../../go/types/testdata/examples", 45, false) } // TODO(gri) narrow column tolerance
 func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", 0, false) }
 
 func testDirFiles(t *testing.T, dir string, colDelta uint, manual bool) {