The ornamental design for a bib, as shown and described.
FIG. 1 is a front perspective view of a bib showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a right side view thereof; and,
FIG. 8 is a front perspective view thereof of the design in the context in which it is intended to be used.
The broken lines in FIG. 8 showing portions of the human form, show the design in use and form no part of the claim. The broken lines, in FIGS. 1-3, and 8, on the surface bib represent stitching, which forms no part of the claimed design.