Add assembler for riscv64, part 1. Test: m test-art-host-gtest Bug: 271573990 Signed-off-by: Lifang Xia <lifang_xia@linux.alibaba.com> Signed-off-by: Wendong Wang <wangwd@xcvmbyte.com> Signed-off-by: Cao Xia <caoxia@eswincomputing.com> Change-Id: Ie1306521b8df28173b9be40f754e114bd849985b