The ornamental design for a weightliftingbench, as shown and described.
FIG. 1 is a top, front, left perspective view of a weightlifting bench showing our new design;
FIG. 2 is a bottom, front, left perspective view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a front view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The broken lines immediately adjacent to the shaded areas define the bounds of the claimed design and form no part thereof. The broken lines depicting the remainder of the weightlifting bench show features that form no part of the claimed design.