[clang] [clang-tools-extra] [llvm] [clang]: reflection operator parsing for global namespace and primitive types (PR #164692)

[Hubert Tong via cfe-commits]

================
@@ -5501,6 +5501,60 @@ class BuiltinBitCastExpr final
   }
 };
 
+/// Represents a C++26 reflect expression [expr.reflect]. The operand of of the
+/// expression is either a:
+///  - :: (global namespace)
+///  - a reflection-name
+///  - a type-id
+///  - id-expression.
----------------
hubert-reinterpretcast wrote:

```suggestion
/// Represents a C++26 reflect expression [expr.reflect]. The operand of the
/// expression is either:
///  - :: (global namespace),
///  - a reflection-name,
///  - a type-id, or
///  - an id-expression.
```

https://github.com/llvm/llvm-project/pull/164692