Mark FunctionExpression elements as used in DeclarationResolver.

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index c36d1547b411cf9654816332048530cc5c88d7b3..0fb19c164b874c6b6e0be8655fb055d9d9808e22 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -2302,6 +2302,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
     if (node.parent is! FunctionDeclaration) {
       FunctionElement element = _findAtOffset(
           _enclosingExecutable.functions, node, node.beginToken.offset);
+      _expectedElements.remove(element);
       node.element = element;
     }
     ExecutableElement outerExecutable = _enclosingExecutable;