Added missing argument 'size' with default value of -1 to TextIOBase.readline

Author: Saber_0324

Lib/_pyio.py

@@ -1928,7 +1928,7 @@ def truncate(self, pos=None):
         """Truncate size to pos, where pos is an int."""
         self._unsupported("truncate")
 
-    def readline(self):
+    def readline(self, size=-1):
         """Read until newline or EOF.
 
         Returns an empty string if EOF is hit immediately.