I claim the ornamental design for a flashlight, as shown and described.
FIG. 1 is a perspective view of my flashlight;
FIG. 2 is a front view thereof;
FIG. 3 is a back 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; and,
FIG. 7 is a bottom view thereof.
The oblique lines on the lens of my design (as visible in FIGS. 1 and 6) indicate that it is at least translucent and may be transparent. The dashed lines in the figures are for illustrative purposes only and form no part of the claimed design. All other surface(s) or portion(s) of my design not shown in the figures or otherwise described in the specification, such as the locations behind the lens, form no part of the claimed design.