* ieee.c: Add global function write_ieee_debugging_info and a
bunch of static functions and structs used to write out IEEE
debugging information.
* budbg.h (write_ieee_debugging_info): Declare.
* ieee.c (struct ieee_type): Add pslot field.
(enum builtin_types): Define.
(ieee_builtin_type): For a pointer, return a pointer to the named
type. Use enum values rather than numbers.
(ieee_alloc_type): New static function.
(ieee_read_type_index): Use ieee_alloc_type.
(parse_ieee_bb): Likewise.
(parse_ieee_ty): Likewise. Use ieee_builtin_type for array range,
rather than making a new integer type. Store the new type in the
slot, if there is one.
(parse_ieee_atn): Treat ATN10 as defining a register variable.
(ieee_regno_to_genreg): Rename from ieee_regno_to_gen. Change all
callers.
(ieee_genreg_to_regno): New static function.