pyassem: Initialize namespace vars.

Before iterating and changing namespace, to avoid "dictionary changed
while iterating" error.

Author: pfalcon

compiler/pyassem.py

@@ -496,6 +496,7 @@ def _convert_COMPARE_OP(self, arg):
 
     # similarly for other opcodes...
 
+    name = obj = opname = None
     for name, obj in locals().items():
         if name[:9] == "_convert_":
             opname = name[9:]