[llvm] [SandboxIR][NFC] Move sandboxir::Use into a separate file (PR #99074)

[Thorsten Schütt via llvm-commits]

================
@@ -0,0 +1,52 @@
+#ifndef LLVM_TRANSFORMS_SANDBOXIR_USE_H
+#define LLVM_TRANSFORMS_SANDBOXIR_USE_H
+
+#include "llvm/IR/Use.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+namespace sandboxir {
+
+class Context;
+class Value;
+class User;
+
+/// Represents a Def-use/Use-def edge in SandboxIR.
+/// NOTE: Unlike llvm::Use, this is not an integral part of the use-def chains.
+/// It is also not uniqued and is currently passed by value, so you can have
+/// more than one sandboxir::Use objects for the same use-def edge.
+class Use {
+  llvm::Use *LLVMUse;
+  User *Usr;
+  Context *Ctx;
+
+  /// Don't allow the user to create a sandboxir::Use directly.
+  Use(llvm::Use *LLVMUse, User *Usr, Context &Ctx)
+      : LLVMUse(LLVMUse), Usr(Usr), Ctx(&Ctx) {}
+  Use() : LLVMUse(nullptr), Ctx(nullptr) {}
+
+  friend class Value;              // For constructor
+  friend class User;               // For constructor
+  friend class OperandUseIterator; // For constructor
+  friend class UserUseIterator;    // For accessing members
+
+public:
+  operator Value *() const { return get(); }
+  Value *get() const;
+  class User *getUser() const { return Usr; }
+  unsigned getOperandNo() const;
+  Context *getContext() const { return Ctx; }
+  bool operator==(const Use &Other) const {
+    assert(Ctx == Other.Ctx && "Contexts differ!");
+    return LLVMUse == Other.LLVMUse && Usr == Other.Usr;
+  }
+  bool operator!=(const Use &Other) const { return !(*this == Other); }
+#ifndef NDEBUG
+  void dump(raw_ostream &OS) const;
+  void dump() const;
+#endif // NDEBUG
+};
----------------
tschuett wrote:

A newline would be nice, but ...

https://github.com/llvm/llvm-project/pull/99074