The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a front perspective view of a shoe upper showing my new design;
FIG. 2 is a side view thereof; and,
FIG. 3 is a rear perspective view thereof.
The uneven-length broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The even-length broken lines within the shaded area represent stitching that forms no part of the claimed design. The uneven-length broken lines showing the remainder of the shoe are for environmental purposes only and form no part of the claimed design.