[ConstraintSystem] Make getCalleLocator to support an apply involving an dynamicCallable

Author: LucianoPAlmeida

lib/Sema/ConstraintSystem.cpp

@@ -513,6 +513,13 @@ ConstraintLocator *ConstraintSystem::getCalleeLocator(
                                   {LocatorPathElt::ApplyFunction(),
                                    LocatorPathElt::ImplicitCallAsFunction()});
     }
+
+    // Handling an apply for a nominal type that supports @dynamicCallable.
+    auto nominal = fnTy->getAnyNominal();
+    if (nominal && nominal->getAttrs().hasAttribute<DynamicCallableAttr>()) {
+      return getConstraintLocator(anchor, LocatorPathElt::ApplyFunction());
+    }
+
     return nullptr;
   };