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 rear perspective view thereof;
FIG. 3 is a side view thereof;
FIG. 4 is a second side view thereof; and,
FIG. 5 is a rear view thereof.
The broken lines immediately adjacent to the shaded areas represent unclaimed boundaries of the design. The unshaded regions, demarcated by broken lines, within the shaded area form no part of the claimed design. The broken lines showing the remainder of the shoe are for environmental purposes only and form no part of the claimed design.