[llvm] [CodeGen] Introduce a RegisterUnit class to hold virtual reg or physical reg unit. NFC (PR #123768)

[Sergei Barannikov via llvm-commits]

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@@ -160,6 +160,37 @@ template <> struct DenseMapInfo<Register> {
   }
 };
 
+/// Wrapper class representing a virtual register or register unit.
+class RegisterUnit {
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s-barannikov wrote:

The name is still confusing. Maybe `VRegOrUnit` and `VRU` for variable names? (Couldn't come up with anything much better.)


https://github.com/llvm/llvm-project/pull/123768