The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a top perspective view of the shoe upper from the lateral side;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a medial side view thereof;
FIG. 5 is lateral side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
Longer broken lines shown in the drawings of the shoe upper represent stitching and form no part of the claimed design. Shorter broken lines shown in the drawings of the shoe upper illustrate the environment of the claimed design and also form no part of the claimed design.