Revive not_constexpr checks

Author: ckoparkar

libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-clang.pass.cpp

@@ -201,6 +201,8 @@ int main(int, char**) {
   ASSERT_NOT_CONSTEXPR_CXX23(std::fmaf(1.0f, 1.0f, 1.0f) == 2.0f);
   ASSERT_NOT_CONSTEXPR_CXX23(std::fmal(1.0L, 1.0L, 1.0L) == 2.0L);
 #else
+  ASSERT_NOT_CONSTEXPR_CXX23(std::fma(1.0f, 1.0f, 1.0f) == 2.0f);
+  ASSERT_NOT_CONSTEXPR_CXX23(std::fma(1.0L, 1.0L, 1.0L) == 2.0L);
   ASSERT_CONSTEXPR_CXX23(std::fma(1.0, 1.0, 1.0) == 2.0);
   ASSERT_CONSTEXPR_CXX23(std::fmaf(1.0f, 1.0f, 1.0f) == 2.0f);
   ASSERT_CONSTEXPR_CXX23(std::fmal(1.0L, 1.0L, 1.0L) == 2.0L);