(resolve_symbol_value, case O_symbol): Don't do any processing if add_symbol is

(resolve_symbol_value, case O_symbol): Don't do any processing if add_symbol is
undefined or in expr_section.
(resolve_symbol_value, case O_add): For symbol plus constant-valued symbol,
convert to O_symbol and re-reduce.
(S_GET_VALUE): If symbol needs resolving, resolve it.

(indent_level): No longer static.
(print_symbol_value_1): Don't print frag address if it matches
zero_address_frag.  Don't print "resolving" if already resolved.  Print segment
name.  Don't call print_expr_1 on an undefined symbol.
(print_expr_1): Fix whitespace before printing X_add_number.