[llvm] [TableGen] Use llvm::enumerate in one place (NFC) (PR #136399)

[Sergei Barannikov via llvm-commits]

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@@ -200,26 +200,24 @@ CodeGenInstAlias::CodeGenInstAlias(const Record *R, const CodeGenTarget &T)
 
   // Decode and validate the arguments of the result.
   unsigned AliasOpNo = 0;
-  for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
-
+  for (auto [OpIdx, OpInfo] : enumerate(ResultInst->Operands)) {
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s-barannikov wrote:

FWIW the size of the structure appears to be just 16 bytes.
![image](https://github.com/user-attachments/assets/8e7a3461-2620-4a26-a357-9ec640f90126)


https://github.com/llvm/llvm-project/pull/136399