We claim the ornamental design for a trouser stretcher, as shown and described.
FIG. 1 is a front perspective view of a trouser stretcher showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left-side view thereof;
FIG. 5 is a right-side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a cross-sectional view taken along the line 8-8 of FIG. 2; and,
FIG. 9 is a perspective view of the trouser stretcher shown in a state of use.
The broken lines in the figures depict portions of the trouser stretcher which form no part of the claimed design. The remaining broken lines depict environmental subject matter and form no part of the claimed design.