* exp_ch9.adb (Expand_Entry_Barrier): Code
cleanup. Do not perform the optimization which removes the
declarations of the discriminant and component renamings when
validity checks on operands and attributes are in effect.
* g-debpoo.adb (Dump_Gnatmem): Protect against a possible null
pointer dereference.
* g-spipat.adb (Dump): Code clean up. Protect against a possible
null pointer dereference.