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 side view thereof; and,
FIG. 3 is a rear perspective view thereof.
The photographic area is claimed. The broken lines immediately adjacent to the photographic area represent unclaimed boundaries of the design. The unshaded regions within the photographic area that are demarcated by broken lines form no part of the claimed design. The broken lines showing the remainder of the shoe represent unclaimed subject matter and form no part of the claimed design.