* mdebugread.c (parse_symbol): Use new variable
nodebug_var_symbol_type as type of variables which don't have any
ecoff debug info associated with them.
(parse_symbol, parse_procedure): Use heuristics to determine if
functions were compiled without debugging info and change their
type to nodebug_function_symbol_type.
(_initialize_mdebugread): Initialize nodebug_*_symbol_type.
* source.c (line_info): Clear sal.pc for `info line' without
arguments.