[llvm] [RISCV][NFC] Use !range bang operator (PR #66494)

[Shao-Ce SUN via llvm-commits]

================
@@ -416,12 +416,11 @@ class VRegList<list<dag> LIn, int start, int nf, int lmul, bit isV0> {
 }
 
 // Vector registers
-foreach Index = 0-31 in {
+foreach Index = !range(0, 32, 1) in {
----------------
sunshaoce wrote:

If you want to do this kind of rewriting, then there are still many similar codes in this file.

https://github.com/llvm/llvm-project/pull/66494