[llvm] [RISCV] Remove vmv.s.x and vmv.x.s lmul pseudo variants (PR #71501)

[Luke Lau via llvm-commits]

================
@@ -487,9 +487,9 @@ define <4 x i8> @unary_interleave_v4i8_invalid(<4 x i8> %x) {
 ; V512:       # %bb.0:
 ; V512-NEXT:    lui a0, 16
 ; V512-NEXT:    addi a0, a0, 768
-; V512-NEXT:    vsetivli zero, 4, e32, mf2, ta, ma
+; V512-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
 ; V512-NEXT:    vmv.s.x v10, a0
-; V512-NEXT:    vsetvli zero, zero, e8, mf8, ta, ma
+; V512-NEXT:    vsetivli zero, 4, e8, mf8, ta, ma
----------------
lukel97 wrote:

Here's a case where a backwards pass of #69259 would help. 

https://github.com/llvm/llvm-project/pull/71501