[llvm] [NFC] Add `const` for readability (PR #116611)

[Piotr Fusik via llvm-commits]

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@@ -581,30 +581,30 @@ class InnerLoopVectorizer {
   virtual void printDebugTracesAtEnd() {}
 
   /// The original loop.
-  Loop *OrigLoop;
+  Loop *const OrigLoop;
 
   /// A wrapper around ScalarEvolution used to add runtime SCEV checks. Applies
   /// dynamic knowledge to simplify SCEV expressions and converts them to a
   /// more usable form.
   PredicatedScalarEvolution &PSE;
 
   /// Loop Info.
-  LoopInfo *LI;
+  LoopInfo *const LI;
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pfusik wrote:

I'm not a fan of putting `const` everywhere, for example on local variables and parameters.
But I see value in saying that a member variable is not mutated after construction. I'm surprised that you weren't aware of this meaning of `const` !
Also, to be clear, it is not my goal to add `const`s here and there, but to understand the code.

https://github.com/llvm/llvm-project/pull/116611