I claim the ornamental design for a poker chip stacking tool, as shown and described.
FIG. 1 is a perspective view of a poker chip stacking tool, showing a first embodiment of my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left-side elevational view thereof, the right-side elevational view being a mirror image thereof;
FIG. 5 is a top plan view thereof, the bottom plan view being a mirror image thereof;
FIG. 6 is a perspective view of a second embodiment thereof; and,
FIG. 7 is a front elevational view of FIG. 6.
The broken lines showing a poker chips in FIG. 4 depict environmental matter and form no part of the claimed design. It is understood that the rear, left-side elevational view, and top plan views of the second embodiment are identical to those of the first embodiment.