The ornamental design for a rearcover for a construction machine, as shown and described.
FIG. 1 is a first perspective view of a rear cover for a construction machine showing our new design;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a top view thereof; and,
FIG. 5 is a bottom view thereof.
The claimed design is indicated by the relatively dark portions in the figures, while the relatively light portions are environmental and form no part of the claimed design.