Add two more tests for _iter_code per #866, capturing the apparent expectation...

Add two more tests for _iter_code per #866, capturing the apparent expectation in the byte-code processing that's now failing on Python 3.6.

setuptools/tests/test_depends.py

@@ -14,3 +14,15 @@ class TestGetModuleConstant:
 		val = depends.get_module_constant(mod_name, 'value')
 		assert val == 'three, sir!'
 		assert 'setuptools.tests.mod_with_constant' not in sys.modules
+
+
+class TestIterCode:
+	def test_empty(self):
+		code = compile('', '<string>', mode='exec')
+		expected = (100, 0), (83, None)
+		assert tuple(depends._iter_code(code)) == expected
+
+	def test_constant(self):
+		code = compile('value = "three, sir!"', '<string>', mode='exec')
+		expected = (100, 0), (90, 0), (100, 1), (83, None)
+		assert tuple(depends._iter_code(code)) == expected