Fix

[ 1124295 ] Function's __name__ no longer accessible in restricted mode

which I introduced with a bit of mindless copy-paste when making
__name__ writable.  You can't assign to __name__ in restricted mode,
which I'm going to pretend was intentional :)
diff --git a/Lib/test/test_funcattrs.py b/Lib/test/test_funcattrs.py
index 1acfeb5..7a083b7 100644
--- a/Lib/test/test_funcattrs.py
+++ b/Lib/test/test_funcattrs.py
@@ -276,6 +276,9 @@
     verify(f.func_name == "h")
     cantset(f, "func_globals", 1)
     cantset(f, "__name__", 1)
+    # test that you can access func.__name__ in restricted mode
+    s = """def f(): pass\nf.__name__"""
+    exec s in {'__builtins__':{}}
 
 
 def test_func_code():