1) longrel() in c11.c - the setting of tree type to LONG after doitover:
and the 'slda' 5 lines after that

2) resolve conversions in c12.c such as ITOL so that if its converting
to an unsigned long the right hand value is cast as an unsigned long.

3) look at ITOL, COMPL and NEG within unoptim within c12.c
