IUO: Update code completion output for constructor result types.

Update the code that prints types for constructor results to take
into account IUO types being removed from the type system.

NFC on master. Results in better fidelity with what we have today when
IUOs are removed from the type system in a future commit.

lib/IDE/CodeCompletion.cpp

@@ -2644,9 +2644,15 @@ public:
 
       addThrows(Builder, ConstructorType, CD);
 
-      addTypeAnnotation(Builder,
-                        Result.hasValue() ? Result.getValue() :
-                                            ConstructorType->getResult());
+      if (CD->getAttrs().hasAttribute<ImplicitlyUnwrappedOptionalAttr>()) {
+        addTypeAnnotationForImplicitlyUnwrappedOptional(
+            Builder, Result.hasValue() ? Result.getValue()
+                                       : ConstructorType->getResult());
+      } else {
+        addTypeAnnotation(Builder, Result.hasValue()
+                                       ? Result.getValue()
+                                       : ConstructorType->getResult());
+      }
     };
 
     if (ConstructorType && hasInterestingDefaultValues(CD))