c++: satisfaction value of type const bool [PR104410]

c++: satisfaction value of type const bool [PR104410]

Here constant evaluation of the atomic constraint use_func_v<T>
sensibly yields an INTEGER_CST of type const bool, but the assert in
satisfaction_value expects unqualified bool.  So let's just relax the
assert to accept cv-qualified bool.

	PR c++/104410

gcc/cp/ChangeLog:

	* constraint.cc (satisfaction_value): Relax assert to accept
	cv-qualified bool.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/concepts-pr104410.C: New test.