The ornamental design for a dumptruck-simulating lighting fixture, as shown and described.
FIG. 1 is a top-side perspective view of a dump truck-simulating lighting fixture showing my new design;
FIG. 2 is a bottom-side perspective view of the opposite side shown in FIG. 1;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The portions of the drawings provided by broken line are intended to reflect environment, and do not form a part of the indicated embodiment of my design.