Implement type inference for assignments to a static variable.

pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart

Index: pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart b/pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart
index b383f6fcbb9b1f6ac8242d2133a30f39788cc18e..f250a951627bee114d4e977f461188922e141159 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart
@@ -230,6 +230,12 @@ class TypeInferenceListener
   void returnStatementExit(ReturnStatement statement) =>
       debugStatementExit('returnStatement', statement);
 
+  bool staticAssignEnter(Expression expression, DartType typeContext) =>
+      debugExpressionEnter("staticAssign", expression, typeContext);
+
+  void staticAssignExit(Expression expression, DartType inferredType) =>
+      debugExpressionExit("staticAssign", expression, inferredType);
+
   bool staticGetEnter(StaticGet expression, DartType typeContext) =>
       debugExpressionEnter("staticGet", expression, typeContext);