Second try: Fix resolution and canonicalization of typedefs and function types

runtime/vm/kernel_to_il.cc

Index: runtime/vm/kernel_to_il.cc
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 2f1b8f2a7ce029b43c95a813ed8ec33b61f86d47..e5d75e77ec317bfbf199602d5f52d3383231451b 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -3953,7 +3953,7 @@ void DartTypeTranslator::VisitFunctionType(FunctionType* node) {
   // So we convert malformed return/parameter types to `dynamic`.
   TypeParameterScope scope(this, &node->type_parameters());
 
-  const Function& signature_function = Function::ZoneHandle(
+  Function& signature_function = Function::ZoneHandle(
       Z, Function::NewSignatureFunction(*active_class_->klass,
                                         TokenPosition::kNoSource));
 
@@ -4008,8 +4008,10 @@ void DartTypeTranslator::VisitFunctionType(FunctionType* node) {
   if (finalize_) {
     signature_type ^= ClassFinalizer::FinalizeType(
         *active_class_->klass, signature_type, ClassFinalizer::kCanonicalize);
+    // Do not refer to signature_function anymore, since it may have been
+    // replaced during canonicalization.
+    signature_function = Function::null();
   }
-  signature_function.SetSignatureType(signature_type);

[regis, 2016/12/28 22:12:18]

This statement was setting the signature type on the replaced signature
function, triggering an assert.

 
   result_ = signature_type.raw();
 }