(st_to_string): Handle them.
(type_to_string): Add fdp argument; pass it to emit_aggregate.
(print_symbol): Add fdp argument; pass it to type_to_string.
Handle st_Struct, st_Union, and st_Enum.
(emit_aggregate): Add fdp argument.  Handle opaque types.  Map through
RFD entries.
(print_file_desc): Pass FDR to print_symbol.
(main): Pass null FDR to type_to_string.

From-SVN: r10516