[llvm] [RISCV] Teach RISCVInsertVSETVLI to work without LiveIntervals (PR #94686)

[Luke Lau via llvm-commits]

================
@@ -745,8 +761,8 @@ class VSETVLIInfo {
     if (Other.isUnknown())
       return isUnknown();
 
-    if (!hasSameAVL(Other))
-      return false;
+    if (!hasSameAVLLatticeValue(Other))
----------------
lukel97 wrote:

There are still some users of == that I think we need to switch over from the notion of lattice value equality to runtime value equality, see VSETVLIInfo:: intersect/needVSETVLIPHI/emitVSETVLIs

They currently work in main because no unknowns reach them but I'm not sure if this will be correct after the nullable ValNo change.

So I think we still need #94340 or something to that effect.

https://github.com/llvm/llvm-project/pull/94686