Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/rasta/issue_000048.dart.dartk.expect

-library;
-import self as self;
-import "dart:core" as core;
-
-class A extends core::Object {
-  field core::bool v1;
-  field core::num v2;
-  constructor •(core::bool v1, core::num v2) → dynamic
-    : self::A::v1 = v1, self::A::v2 = v2, super core::Object::•()
-    ;
-}
-class M1 extends core::Object {
-  field core::num v2;
-  constructor •() → self::M1
-    : self::M1::v2 = 0, super core::Object::•();
-}
-class C extends self::A+M1#0 {
-  constructor •(core::bool v1, core::num v2) → dynamic
-    : super self::A+M1#0::•(v1, v2);
-}
-abstract class A+M1#0 extends self::A implements self::M1 {
-  field core::num v2;
-  constructor •(core::bool v1, core::num v2) → dynamic
-    : self::A+M1#0::v2 = 0, super self::A::•(v1, v2);
-}
-static method main() → dynamic {
-  self::C c = new self::C::•(true, 2);
-}