Disassembler (1.12): use B::Concise op_flags and private_flags

t/testplc.sh -v does not use -qq which crashes with 5.18.1d (unknown reasons)
Bytecode: assemble PADLIST entries after the -PADLIST- line

5.18.1d threaded crashes in testplc at an enteriter op_redoop, dependent
on the stdio state. Maybe issue #137
BC: revert rearrangment of PADLIST entries after the -PADLIST- line

walk the pad before $varix = $ix is checked