Merging upstream version 18.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tests/test_expressions.py

@@ -934,5 +934,8 @@ FROM foo""",
         assert dtype.is_type("foo")
         assert not dtype.is_type("bar")
 
+        dtype = exp.DataType.build("a.b.c", udt=True)
+        assert dtype.is_type("a.b.c")
+
         with self.assertRaises(ParseError):
             exp.DataType.build("foo")