Merge and update tests.

Author: Leon Clark

llvm/test/CodeGen/AMDGPU/cttz_zero_undef.ll

@@ -1452,7 +1452,6 @@ define amdgpu_kernel void @v_cttz_i32_sel_ne_bitwidth(ptr addrspace(1) noalias %
 ; VI-LABEL: v_cttz_i8_sel_eq_neg1:
 ; VI:       ; %bb.0:
 ; VI-NEXT:    s_load_dwordx4 s[0:3], s[4:5], 0x24
-; VI-NEXT:    v_mov_b32_e32 v3, 0xff
 ; VI-NEXT:    s_waitcnt lgkmcnt(0)
 ; VI-NEXT:    v_mov_b32_e32 v0, s2
 ; VI-NEXT:    v_mov_b32_e32 v1, s3