[llvm] [BasicAA] Add Vscale GEP decomposition on variable index (PR #69152)

[David Green via llvm-commits]

================
@@ -1165,6 +1204,46 @@ AliasResult BasicAAResult::aliasGEP(
   if (!V1Size.hasValue() || !V2Size.hasValue())
     return AliasResult::MayAlias;
 
+  // VScale Alias Analysis
----------------
davemgreen wrote:

I was hoping that more of the existing code could handle vscales already if they were treated like variables, but I think there might need to be something that know that vscale in the offset is the same as the vscale in the typesize.

https://github.com/llvm/llvm-project/pull/69152