regen/embed.pl: G flag mean NN, NULLOK not reqd

The G flag for a function indicates to not generate a PERL_ARGS_ASSERT
macro for the function.  This macro is the only consumer of the NN and
NULLOK indicators to pointer arguments.  Since the consumer is absent,
there is no need for them, and they shouldn't be required.

This commit does not change the check that If a NN is furnished, the G
flag is illegal.

regen/embed.pl

@@ -165,7 +165,10 @@ sub open_print_header {
             my $n;
             for my $arg ( @args ) {
                 ++$n;
-                if ( $arg =~ /\*/ && $arg !~ /\b(NN|NULLOK)\b/ ) {
+                if (   $args_assert_line
+		    && $arg =~ /\*/
+		    && $arg !~ /\b(NN|NULLOK)\b/ )
+		{
                     warn "$func: $arg needs NN or NULLOK\n";
                     ++$unflagged_pointers;
                 }