The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a rear perspective view of a shoe upper showing my new design;
FIG. 2 is a side view thereof;
FIG. 3 is a second side view thereof;
FIG. 4 is a rear view thereof; and,
FIG. 5 is a top view thereof.
The broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The unshaded regions within or adjacent to the shaded area that are demarcated by broken lines form no part of the claimed design. The broken lines showing the remainder of the shoe represent environment and form no part of the claimed design.