[Sema] Extract @autoclosure diagnostics from type resolver

lib/Sema/CSGen.cpp

@@ -1429,20 +1429,27 @@ namespace {
                           diag::super_with_no_base_class);
     }
 
-    Type resolveTypeReferenceInExpression(TypeRepr *rep) {
+    Type resolveTypeReferenceInExpression(TypeRepr *repr) {
+      TypeLoc loc(repr);
+      return resolveTypeReferenceInExpression(loc);
+    }
+
+    Type resolveTypeReferenceInExpression(TypeLoc &loc) {
       TypeResolutionOptions options(TypeResolverContext::InExpression);
       options |= TypeResolutionFlags::AllowUnboundGenerics;
-      return TypeResolution::forContextual(CS.DC).resolveType(rep,
-                                                              options);
+      bool hadError = CS.TC.validateType(
+          loc, TypeResolution::forContextual(CS.DC), options);
+      return hadError ? Type() : loc.getType();
     }
 
     Type visitTypeExpr(TypeExpr *E) {
       Type type;
       // If this is an implicit TypeExpr, don't validate its contents.
-      if (E->getTypeLoc().wasValidated()) {
-        type = E->getTypeLoc().getType();
-      } else if (auto *rep = E->getTypeRepr()) {
-        type = resolveTypeReferenceInExpression(rep);
+      auto &typeLoc = E->getTypeLoc();
+      if (typeLoc.wasValidated()) {
+        type = typeLoc.getType();
+      } else if (typeLoc.hasLocation()) {
+        type = resolveTypeReferenceInExpression(typeLoc);
       }
 
       if (!type || type->hasError()) return Type();

lib/Sema/TypeCheckPattern.cpp

@@ -773,13 +773,6 @@ static bool validateParameterType(ParamDecl *decl, TypeResolution resolution,
     }
   }
 
-  // If this parameter declaration is marked as `@autoclosure`
-  // let's make sure that its parameter type is indeed a function,
-  // this decision couldn't be made based on type representative
-  // alone because it may be later resolved into an invalid type.
-  if (decl->isAutoClosure())
-    hadError |= !(Ty && Ty->is<FunctionType>());
-
   if (hadError)
     TL.setInvalidType(TC.Context);