2019-10-22  Marc Glisse  <marc.glisse@inria.fr>

gcc/cp/
	* constexpr.c (cxx_eval_builtin_function_call): Only set
	force_folding_builtin_constant_p if manifestly_const_eval.

gcc/testsuite/
	* g++.dg/pr85746.C: New file.

From-SVN: r277292