tests: Add test to check issue #429.

tests/basics/globals-del.py

+"""
+1
+"""
+
+def _f(): pass
+FunctionType = type(_f)
+LambdaType = type(lambda: None)
+CodeType = None
+MappingProxyType = None
+SimpleNamespace = None
+
+def _g():
+    yield 1
+GeneratorType = type(_g())
+
+class _C:
+    def _m(self): pass
+MethodType = type(_C()._m)
+
+BuiltinFunctionType = type(len)
+BuiltinMethodType = type([].append)
+
+del _f
+
+# print only the first 8 chars, since we have different str rep to CPython
+print(str(FunctionType)[:8])
+print(str(BuiltinFunctionType)[:8])