Only set types of conditional expressions in strong mode.

pkg/front_end/testcases/rasta/native_is_illegal.dart.direct.expect

Index: pkg/front_end/testcases/rasta/native_is_illegal.dart.direct.expect
diff --git a/pkg/front_end/testcases/rasta/native_is_illegal.dart.direct.expect b/pkg/front_end/testcases/rasta/native_is_illegal.dart.direct.expect
index a037ff3a5429675b477091c55b0ffbccb9797c61..36cec9b05d3bf5f9ce7639dff4ff1f2ea29ed433 100644
--- a/pkg/front_end/testcases/rasta/native_is_illegal.dart.direct.expect
+++ b/pkg/front_end/testcases/rasta/native_is_illegal.dart.direct.expect
@@ -1,17 +1,16 @@
 library;
 import self as self;
 import "dart:core" as core;
-import "dart:_internal" as _in;
 
 class Bar extends core::Object {
-  @_in::ExternalName::•("Bar_get_x")
-  external get x() → self::Bar;
-  @_in::ExternalName::•("Bar_set_x")
-  external set x(self::Bar value) → dynamic;
-  @_in::ExternalName::•("Bar_f")
-  external method f() → dynamic;
-  @_in::ExternalName::•("Bar_constructor")
-  external static factory •() → self::Bar;
+  get x() → self::Bar
+    return "Bar_get_x";
+  set x(self::Bar value) → dynamic
+    return "Bar_set_x";
+  method f() → dynamic
+    return "Bar_f";
+  static factory •() → self::Bar
+    return "Bar_constructor";
 }
-@_in::ExternalName::•("foo")
-external static method foo() → dynamic;
+static method foo() → dynamic
+  invalid-statement;