Issue #22199: Make get_makefile_filename() available in Lib/sysconfig.py
for 2.7 to match other versions of sysconfig.
diff --git a/Doc/library/sysconfig.rst b/Doc/library/sysconfig.rst
index a745a3d..9dd0b1e 100644
--- a/Doc/library/sysconfig.rst
+++ b/Doc/library/sysconfig.rst
@@ -221,3 +221,7 @@
 .. function:: get_config_h_filename()
 
    Return the path of :file:`pyconfig.h`.
+
+.. function:: get_makefile_filename()
+
+   Return the path of :file:`Makefile`.