tcg/tci: Implement the disassembler properly

tcg/tci: Implement the disassembler properly

Actually print arguments as opposed to simply the opcodes
and, uselessly, the argument counts.  Reuse all of the helpers
developed as part of the interpreter.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>