Move kernel baseline tests to front_end.

pkg/front_end/testcases/expressions.dart.direct.expect

 library;
 import self as self;
 import "dart:core" as core;
 
 static method foo({dynamic fisk = null}) → dynamic {
   core::print(fisk);
 }
 static method caller(dynamic f) → dynamic {
   f.call();
 }
@@ skipping 59 matching lines @@
   core::print(let final dynamic #t5 = core::int in let final dynamic #t6 = #t5.toString() in #t5);
   try {
     core::print(throw new core::NoSuchMethodError::•(null, #toString, <dynamic>[], <dynamic, dynamic>{}, null));
     throw "Shouldn't work";
   }
   on core::NoSuchMethodError catch(final dynamic e) {
     core::print("As expected: ${e}");
   }
   core::print(core::int::parse("42"));
 }