[llvm] [IR][NFC] Add LoadStoreInstAttributes to copy load/store attrs (PR #206470)

[Antonio Frighetto via llvm-commits]

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@@ -172,6 +172,14 @@ class AllocaInst : public UnaryInstruction {
   }
 };
 
+/// A structure representing the attributes of a load or store instruction.
+struct LoadStoreInstAttributes {
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antoniofrighetto wrote:

As originally suggested, let's avoid possible collision with the LLVM attribute concept. It would be also better to define the structure closer to LoadInst class (not here in AllocaInst).

```suggestion
/// A structure representing the properties of a load or store instruction.
struct LoadStoreProperties {
```

https://github.com/llvm/llvm-project/pull/206470