From-SVN: r279813
From-SVN: r267494
Implement P1007R3 std::assume_aligned * include/std/memory (assume_aligned): Implement for C++17. * testsuite/20_util/assume_aligned/1.cc: New test. * testsuite/20_util/assume_aligned/2_neg.cc: New test. * testsuite/20_util/assume_aligned/3.cc: New test. From-SVN: r266009