Fix bug in variable shadowing.
Fix bug in variable shadowing.

Not all variables were translated, which led to wrong code generation.

serge-sans-paille/pythran,pbrunet/pythran,serge-sans-paille/pythran,artas360/pythran,pombredanne/pythran,pombredanne/pythran,hainm/pythran,hainm/pythran,hainm/pythran,pombredanne/pythran,artas360/pythran,pbrunet/pythran,artas360/pythran,pbrunet/pythran