TypeCheckType: Mark misspelled optional existential as invalid

So that is does not show up in other diagnostic passes

Author: AnthonyLatsis

lib/Sema/TypeCheckType.cpp

@@ -5907,6 +5907,10 @@ TypeResolver::resolveExistentialType(ExistentialTypeRepr *repr,
       diagnose(repr->getLoc(), diag::incorrect_optional_any,
                constraintType)
         .fixItReplace(repr->getSourceRange(), fix);
+
+      // Recover by returning the intended type, but mark the type
+      // representation as invalid to prevent it from being diagnosed elsewhere.
+      repr->setInvalid();
       return constraintType;
     }
 
@@ -6348,13 +6352,6 @@ class ExistentialTypeSyntaxChecker : public ASTWalker {
         continue;
       }
 
-      // Look through '?' and '!' too; `any P?` et al. is diagnosed in the
-      // type resolver.
-      if (isa<OptionalTypeRepr>(*it) ||
-          isa<ImplicitlyUnwrappedOptionalTypeRepr>(*it)) {
-        continue;
-      }
-
       break;
     }