Merge pull request #31654 from xedin/rdar-62989214

[ConstraintSystem] Look through key path dynamic lookup nodes while s…

lib/Sema/ConstraintSystem.cpp

@@ -3505,6 +3505,12 @@ void constraints::simplifyLocator(ASTNode &anchor,
       continue;
     }
 
+    case ConstraintLocator::KeyPathDynamicMember: {
+      // Key path dynamic member lookup should be completely transparent.
+      path = path.slice(1);
+      continue;
+    }
+
     default:
       // FIXME: Lots of other cases to handle.
       break;