[RISCV] Check that VLMAX is the same when demanding exact VL (#89080)

Author: lukel97

llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp

@@ -616,7 +616,7 @@ class VSETVLIInfo {
     if (SEWLMULRatioOnly)
       return false;
 
-    if (Used.VLAny && !hasSameAVL(Require))
+    if (Used.VLAny && !(hasSameAVL(Require) && hasSameVLMAX(Require)))
       return false;
 
     if (Used.VLZeroness && !hasEquallyZeroAVL(Require, MRI))