The ornamental design for a constructiontool, as shown and described.
FIG. 1 is a front perspective view of a construction tool, showing the new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines shown in the drawing views are included for the purpose of illustrating portions of the construction tool that form no part of the claimed design.