Order scope.buffer_vars by name

Cython/Compiler/Buffer.py

@@ -50,6 +50,7 @@ class IntroduceBufferAuxiliaryVars(CythonTransform):
                    in scope.entries.iteritems()
                    if entry.type.is_buffer]
         if len(bufvars) > 0:
+            bufvars.sort(key=lambda entry: entry.name)
             self.buffers_exists = True
 
         memviewslicevars = [entry for name, entry
@@ -745,4 +746,4 @@ acquire_utility_code = load_buffer_utility("BufferFormatCheck",
 _typeinfo_to_format_code = load_buffer_utility("TypeInfoToFormat", context={},
                                                requires=[buffer_structs_code])
 typeinfo_compare_code = load_buffer_utility("TypeInfoCompare", context={},
-                                            requires=[buffer_structs_code])
\ No newline at end of file
+                                            requires=[buffer_structs_code])