Merge pull request #3491 from Raku/document-HAS

Index HAS

Author: JJ

doc/Language/nativecall.pod6

@@ -450,7 +450,7 @@ say nativesizeof(MyUnion.new);  # OUTPUT: «8␤»
                                 # ie. max(sizeof(MyUnion.flags32), sizeof(MyUnion.flags64))
 =end code
 
-=head2 Embedding CStructs and CUnions
+=head2 Embedding CStructs and CUnions with X<C<HAS>,declarator>
 
 C<CStruct>s and C<CUnion>s can be in turn referenced by—or embedded into—a
 surrounding C<CStruct> and C<CUnion>. To say the former we use C<has>