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; and,
FIG. 2 is a front view thereof.
The broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The even-length broken lines within the shaded area represent unclaimed stitching. The broken lines showing the remainder of the shoe are for environmental purposes only and form no part of the claimed design.