[llvm] [NFC][TableGen] Adopt CodeGenHelpers in RegInfoEmitter (PR #179017)

[Ivan Kosarev via llvm-commits]

================
@@ -106,10 +106,21 @@ class NamespaceEmitter {
     Name.consume_front("::");
     return Name;
   }
+
   std::string Name;
   raw_ostream &OS;
 };
 
+// Simple RAII helper for emitting anonymous namespace scope.
+class AnonNamespaceEmitter {
+public:
+  AnonNamespaceEmitter(raw_ostream &OS) : OS(OS) { OS << "namespace {\n\n"; }
+  ~AnonNamespaceEmitter() { OS << "} // namespace\n"; }
----------------
kosarev wrote:

Nit:

```suggestion
  ~AnonNamespaceEmitter() { OS << "} // anonymous namespace\n"; }
```

https://github.com/llvm/llvm-project/pull/179017