describing enum.
* defs.h: added new #define for TARGET_PTR_BIT, defaults to size
of target int.
* h8300-tdep.c, remote-hms.c, tm-h8300.h: too many changes to count
* symtab.c (lookup_reference_type, lookup_ptr_type): use
TARGET_PTR_BIT to determine size of a pointer
* values.c (unpack_long): when unpacking a REF or a PTR don't
assume the size of the type.