pragma Debug_Policy (CHECK | DISABLE | IGNORE);
If the argument is CHECK, then pragma DEBUG is enabled.
If the argument is IGNORE, then pragma DEBUG is ignored.
This pragma overrides the effect of the -gnata switch on the
command line.
The implementation defined policy DISABLE is like
IGNORE except that it completely disables semantic
checking of the argument to pragma Debug. This may
be useful when the pragma argument references subprograms
in a with'ed package which is replaced by a dummy package
for the final build.