Luis Javier Merino authored May 24, 2021 and Kurt Hindenburg committed May 24, 2021

A new assert in GCC 11.1.0 std::piecewise_linear_distribution fails in
the case that the lower and upper boundaries are equal.  So, make sure
to not construct a std::piecewise_linear_distribution when minSaturation
equals maxSaturation and when minLightness equals maxLightness.

BUG: 434892