Fix inference test annotation of named/optional parameters in function types.

pkg/front_end/testcases/inference/inferred_type_uses_synthetic_function_type_positional_param.dart.strong.expect

Index: pkg/front_end/testcases/inference/inferred_type_uses_synthetic_function_type_positional_param.dart.strong.expect
diff --git a/pkg/front_end/testcases/inference/inferred_type_uses_synthetic_function_type_positional_param.dart.strong.expect b/pkg/front_end/testcases/inference/inferred_type_uses_synthetic_function_type_positional_param.dart.strong.expect
new file mode 100644
index 0000000000000000000000000000000000000000..819899880c8c8597f19ddf24ea141e5c27b11a90
--- /dev/null
+++ b/pkg/front_end/testcases/inference/inferred_type_uses_synthetic_function_type_positional_param.dart.strong.expect
@@ -0,0 +1,12 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static field core::List<([core::int]) → core::Object> v = <([core::int]) → core::Object>[self::f, self::g];
+static method f([core::int x = null]) → core::int
+  return null;
+static method g([core::int x = null]) → core::String
+  return null;
+static method main() → dynamic {
+  self::v;
+}