The ornamental design for a bib, as shown and described.
FIG. 1 is a right front top perspective view of a bib embodying the new design.
FIG. 2 is a front elevational view thereof.
FIG. 3 is a rear elevational view thereof.
FIG. 4 is a right side elevational view thereof.
FIG. 5 is a left side elevational view thereof.
FIG. 6 is a top plan view thereof.
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a left front top perspective view thereof shown in a state of use.
The broken lines depicting a baby, in FIG. 8, illustrates environmental structure that forms no part of the claimed design. All other broken lines illustrate portions of the Bib that form no part of the claimed design.