[NFC] Fill out the ASTDumper for TypeReprs

Dump Optional, IUO, OpaqueResult and FixedType reprs.

Author: CodaFi

lib/AST/ASTDumper.cpp

@@ -2987,6 +2987,41 @@ class PrintTypeRepr : public TypeReprVisitor<PrintTypeRepr> {
     printRec(T->getBase());
     PrintWithColorRAII(OS, ParenthesisColor) << ')';
   }
+
+  void visitOptionalTypeRepr(OptionalTypeRepr *T) {
+    printCommon("type_optional") << '\n';
+    printRec(T->getBase());
+    PrintWithColorRAII(OS, ParenthesisColor) << ')';
+  }
+
+  void visitImplicitlyUnwrappedOptionalTypeRepr(
+      ImplicitlyUnwrappedOptionalTypeRepr *T) {
+    printCommon("type_implicitly_unwrapped_optional") << '\n';
+    printRec(T->getBase());
+    PrintWithColorRAII(OS, ParenthesisColor) << ')';
+  }
+
+  void visitOpaqueReturnTypeRepr(OpaqueReturnTypeRepr *T) {
+    printCommon("type_opaque_return");
+    printRec(T->getConstraint());
+    PrintWithColorRAII(OS, ParenthesisColor) << ')';
+  }
+
+  void visitFixedTypeRepr(FixedTypeRepr *T) {
+    printCommon("type_fixed");
+    auto Ty = T->getType();
+    if (Ty) {
+      auto &srcMgr =  Ty->getASTContext().SourceMgr;
+      if (T->getLoc().isValid()) {
+        OS << " location=@";
+        T->getLoc().print(OS, srcMgr);
+      } else {
+        OS << " location=<<invalid>>";
+      }
+    }
+    OS << " type="; Ty.dump(OS);
+    PrintWithColorRAII(OS, ParenthesisColor) << ')';
+  }
 };
 
 } // end anonymous namespace