The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a front, left perspective view of a shoe upper, showing my new design;
FIG. 2 is a rear, right perspective view thereof;
FIG. 3 is a rear elevational view thereof; and,
FIG. 4 is a rear, left perspective view thereof.
The broken lines immediately adjacent to the photographic area represent unclaimed boundaries of the design. The broken lines showing the remainder of the shoe are for environmental purposes only and form no part of the claimed design.