The ornamental design for a personal enclosure, as shown and described.
FIG. 1 is a perspective view of the front of a transparent personal enclosure (provided in an environment in which it is used as a shower stall), mounted against a flat wall, in accordance with the present invention;
FIG. 2 is a top view of the personal enclosure shown in FIG. 1;
FIG. 3 is a side view of the personal enclosure shown in FIG. 1 (i.e., from the side at which a person would enter the personal enclosure); and,
FIG. 4 is a front view of the personal enclosure shown in FIG. 1 (i.e., a view taken from the same side as in FIG. 1).
The broken line showing of a wall and sink is for illustrative purposes only and forms no part of the claimed design.