Move FieldType into anonymous namespace

Author: tbkka

stdlib/public/runtime/ReflectionMirror.mm

@@ -80,6 +80,15 @@ int asprintf(char **strp, const char *fmt, ...) {
 
 using namespace swift;
 
+#if SWIFT_OBJC_INTEROP
+// Declare the debugQuickLookObject selector.
+@interface DeclareSelectors
+- (id)debugQuickLookObject;
+@end
+#endif
+
+namespace {
+
 class FieldType {
   const Metadata *type;
   bool indirect;
@@ -103,15 +112,6 @@ void setReferenceOwnership(TypeReferenceOwnership newOwnership) {
   }
 };
 
-#if SWIFT_OBJC_INTEROP
-// Declare the debugQuickLookObject selector.
-@interface DeclareSelectors
-- (id)debugQuickLookObject;
-@end
-#endif
-
-namespace {
-
 /// The layout of Any.
 using Any = OpaqueExistentialContainer;