The ornamental design for a cordless impactscrewdriver, as shown and described.
FIG. 1 is a left, front perspective view of a cordless impact screwdriver according to the design;
FIG. 2 is a right, rear perspective view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a front view thereof; and,
FIG. 8 is a rear view thereof.
The even broken lines in the drawings illustrate portions of the cordless impact screwdriver that form no part of the claimed design. The dash-dot broken line in the drawings illustrates the boundaries of the claim and forms no part thereof.