Allow this?.foo (again)

pkg/compiler/lib/src/resolution/members.dart

Index: pkg/compiler/lib/src/resolution/members.dart
diff --git a/pkg/compiler/lib/src/resolution/members.dart b/pkg/compiler/lib/src/resolution/members.dart
index 1bd64f232b073b3fa36cadc1d227bba1cb1d5521..6b34348c1db538301f64b70c243e631ab1f9352f 100644
--- a/pkg/compiler/lib/src/resolution/members.dart
+++ b/pkg/compiler/lib/src/resolution/members.dart
@@ -800,11 +800,6 @@ class ResolverVisitor extends MappingVisitor<ResolutionResult> {
       compiler.reportError(node, MessageKind.NO_THIS_AVAILABLE);
       return false;
     }
-    if (node.isConditional) {
-      // `this?.foo` is not allowed.
-      compiler.reportError(node, MessageKind.INVALID_USE_OF_THIS);
-      return false;
-    }
     return true;
   }