The ornamental design for a luminaire, as shown and described.
FIG. 1 is a bottom perspective view of the luminaire of the present invention, with visible non-outer surface portions of the luminaire being shown as viewed through the outer surface of the luminaire;
FIG. 2 is a side view of the design of the present invention with visible non-outer surface portions of the luminaire being shown as viewed through the outer surface of the luminaire. All the claimed portions of the sides are mirror images of the others, so no other side views are depicted;
FIG. 3 is a bottom view of the design of the present invention with visible non-outer surface portions of the luminaire being shown as viewed through the outer surface of the luminaire; and,
FIG. 4 is a section view of the luminaire of the present invention taken along the section line 4-4 of FIG. 3 and more clearly showing the non-outer surface portions of the luminaire that are visible through the outer surface of the luminaire.
The broken lines showing environmental structure are for illustrative purposes only and form no part of the claimed design.