[clang][NFC] Convert Sema::TUFragmentKind to scoped enum

clang/include/clang/Sema/Sema.h

@@ -484,6 +484,18 @@ enum class PragmaOptionsAlignKind {
   Reset    // #pragma options align=reset
 };
 
+enum class TUFragmentKind {
+  /// The global module fragment, between 'module;' and a module-declaration.
+  Global,
+  /// A normal translation unit fragment. For a non-module unit, this is the
+  /// entire translation unit. Otherwise, it runs from the module-declaration
+  /// to the private-module-fragment (if any) or the end of the TU (if not).
+  Normal,
+  /// The private module fragment, between 'module :private;' and the end of
+  /// the translation unit.
+  Private
+};
+
 /// Sema - This implements semantic analysis and AST building for C.
 /// \nosubgrouping
 class Sema final : public SemaBase {
@@ -635,18 +647,6 @@ public:
   // Emit all deferred diagnostics.
   void emitDeferredDiags();
 
-  enum TUFragmentKind {
-    /// The global module fragment, between 'module;' and a module-declaration.
-    Global,
-    /// A normal translation unit fragment. For a non-module unit, this is the
-    /// entire translation unit. Otherwise, it runs from the module-declaration
-    /// to the private-module-fragment (if any) or the end of the TU (if not).
-    Normal,
-    /// The private module fragment, between 'module :private;' and the end of
-    /// the translation unit.
-    Private
-  };
-
   /// This is called before the very first declaration in the translation unit
   /// is parsed. Note that the ASTContext may have already injected some
   /// declarations.