Implement function-typed formal parameters in OutlineBuilder.

pkg/front_end/lib/src/fasta/source/outline_builder.dart

Index: pkg/front_end/lib/src/fasta/source/outline_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/source/outline_builder.dart b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
index 4cffd0ea693c06ffa6e59b123ff41ac9d3a13935..04e2185071bc4582ffe61b29d3a600d06576ec9f 100644
--- a/pkg/front_end/lib/src/fasta/source/outline_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
@@ -510,13 +510,14 @@ class OutlineBuilder extends UnhandledListener {
   void endFunctionTypedFormalParameter(
       Token covariantKeyword, Token thisKeyword, FormalParameterType kind) {
     debugEvent("FunctionTypedFormalParameter");
-    pop(); // Function type parameters.
-    pop(); // Formals offset
-    pop(); // Type variables.
+    List<FormalParameterBuilder> formals = pop();
+    int formalsOffset = pop();
+    List<TypeVariableBuilder> typeVariables = pop();
     int charOffset = pop();
     String name = pop();
-    pop(); // Return type.
-    push(NullValue.Type);
+    TypeBuilder returnType = pop();
+    push(library.addFunctionType(
+        returnType, typeVariables, formals, formalsOffset));
     push(name);
     push(charOffset);
   }