GH-102341: Improve the test function for pow (GH-102342)

(cherry picked from commit 32220543e2db36c6146ff2704ed1714a6adecc1b)

Co-authored-by: Partha P. Mukherjee <ppm.floss@gmail.com>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
1 file changed