RISCV: [Codegen] Add GenerateNop

Test: m test-art-host-gtest
Bug: 283082089
Signed-off-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Wendong Wang <wangwd@xcvmbyte.com>
Change-Id: Iaa62836e1b322243abcaa314efb570f65272a834
1 file changed