The ornamental design for a doll, as shown and described.
FIG. 1 is a front, and side perspective view of the doll and support showing our new design, the design is shown in a first representative embodiment.
FIG. 2 is a front elevational view thereof.
FIG. 3 is a back elevational view thereof; and,
FIG. 4 is a top view thereof.
The broken lines showing hair in the drawings are for illustrative purposes only and do not form part of the claimed design. The other broken lines shown on the doll in FIGS. 1 and 4 represent stitching. The stitching on the doll is part of the claimed design.