[GNATS 26284] Spurious diagnostic for invalid type converstion

[jhsedg]

Customer bug ID

26284.C (full preprocessed test) math/test/test_instantiate_no_eh.test/test_instantiate1.o and 2

Description

​In my cp_gen config this fails to compile. In my cgen config it does compile.
​
​[ellen@lin1 status]$ (boost-cpgen)$CPFEA --c++20 --gnu_version=120100 -w -tused p.C
​"../boost/math/concepts/distributions.hpp", line 53: error: invalid type
​ conversion
​ return reinterpret_cast<distribution_archetype>(nullptr);
​ ^
​
​1 error detected in the compilation of "p.C".