Wrong order of PUTGET operands in JS interpreter

[stasoid]

PUTGET in JS interpreter first pops x, then y. John's and Milo's interpreters pop y first.
Looking at the code one might think that John's interpreter pops x first, but because of this bug it's the other way around.

The following program prints A in John's and Milo's interpreters, but JS interpreter prints Z instead.

xA                      x
Zx                     xx
  x                   x x
   x                 x  x
    x               x   x
     x             x    x
      x      x    x     x
       x      x  x    xx
        x      x x   x
         x      xx   x
          x      x  x
           x        x
            x      x
             x     x
              x  xx
               xx

Try John's online.
Try Milo's online.
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