Set hasImplicitReturnType for variable initializer functions.

pkg/analyzer/lib/src/dart/element/builder.dart

Index: pkg/analyzer/lib/src/dart/element/builder.dart
diff --git a/pkg/analyzer/lib/src/dart/element/builder.dart b/pkg/analyzer/lib/src/dart/element/builder.dart
index 17133454c89017c426163beebcdbccabbed15214..7449de14ad0fc6bd9302237570c9efd42fff87b7 100644
--- a/pkg/analyzer/lib/src/dart/element/builder.dart
+++ b/pkg/analyzer/lib/src/dart/element/builder.dart
@@ -557,6 +557,7 @@ class ElementBuilder extends RecursiveAstVisitor<Object> {
       _visit(holder, defaultValue);
       FunctionElementImpl initializer =
           new FunctionElementImpl.forOffset(defaultValue.beginToken.offset);
+      initializer.hasImplicitReturnType = true;
       initializer.functions = holder.functions;
       initializer.labels = holder.labels;
       initializer.localVariables = holder.localVariables;
@@ -1158,6 +1159,7 @@ class ElementBuilder extends RecursiveAstVisitor<Object> {
       _visit(holder, node.initializer);
       FunctionElementImpl initializer =
           new FunctionElementImpl.forOffset(node.initializer.beginToken.offset);
+      initializer.hasImplicitReturnType = true;
       initializer.functions = holder.functions;
       initializer.labels = holder.labels;
       initializer.localVariables = holder.localVariables;