[CSSimplify] Fail when try do simplify a key path application to a key path dynamicMemberLookup

Author: LucianoPAlmeida

lib/Sema/CSSimplify.cpp

@@ -7802,6 +7802,12 @@ ConstraintSystem::simplifyKeyPathApplicationConstraint(
     return SolutionKind::Unsolved;
   };
 
+  // When locator points to a KeyPathDynamicMemberLookup, skip the
+  // key path application.
+  if (locator.getBaseLocator()->isForKeyPathDynamicMemberLookup()) {
+    return SolutionKind::Error;
+  }
+  
   if (auto clas = keyPathTy->getAs<NominalType>()) {
     if (clas->getDecl() == getASTContext().getAnyKeyPathDecl()) {
       // Read-only keypath, whose projected value is upcast to `Any?`.