Fix unittest.mock._Call: don't ignore name (#307)

Issue #28961: Fix unittest.mock._Call helper: don't ignore the name parameter
anymore.

Patch written by Jiajun Huang.

(cherry picked from commits 84b6fb0eea
and dea1536fd3)

Conflicts:

	Misc/NEWS

Lib/unittest/mock.py

@@ -1945,9 +1945,8 @@ class _Call(tuple):
 
     If the _Call has no name then it will match any name.
     """
-    def __new__(cls, value=(), name=None, parent=None, two=False,
+    def __new__(cls, value=(), name='', parent=None, two=False,
                 from_kall=True):
-        name = ''
         args = ()
         kwargs = {}
         _len = len(value)