luac 5.2.0work3 crash on printing stripped bytecodes with upvalues

[David Manura <dm.lua@...>]

This crashes on Lua 5.2.0work3:

  (echo 'x=1' | luac -s - ) && luac -l

on print.c:126:

  case OP_SETTABUP:
  =>printf("\t; %s", (f->sizeupvalues>0) ? getstr(f->upvalues[a].name) : "-");

with f->sizeupvalues == 1.  Appears related to printing upvalues in
bytecodes stripped of debugging info.

The reason I tried this was to determine whether gets/sets to globals
can still be detected in stripped bytecodes under the removal of
SETGLOBAL/GETGLOBAL opcodes in Lua 5.2.0work3 (related to [1]).

[1] http://lua-users.org/lists/lua-l/2010-07/msg00062.html