[RISCV] Select Zvkb VANDN for shorter constant loading sequences

This extends PR llvm#120221 to vector instructions.

Author: pfusik

llvm/lib/Target/RISCV/RISCVInstrInfoZvk.td

@@ -624,6 +624,13 @@ foreach vti = AllIntegerVectors in {
                  vti.RegClass:$rs2,
                  vti.ScalarRegClass:$rs1,
                  vti.AVL, vti.Log2SEW, TA_MA)>;
+    def : Pat<(vti.Vector (and (riscv_splat_vector invLogicImm:$rs1),
+                               vti.RegClass:$rs2)),
+              (!cast<Instruction>("PseudoVANDN_VX_"#vti.LMul.MX)
+                 (vti.Vector (IMPLICIT_DEF)),
+                 vti.RegClass:$rs2,
+                 invLogicImm:$rs1,
+                 vti.AVL, vti.Log2SEW, TA_MA)>;
   }
 }