Move kernel baseline tests to front_end.

pkg/kernel/testcases/spec-mode/argument.baseline.txt

Index: pkg/kernel/testcases/spec-mode/argument.baseline.txt
diff --git a/pkg/kernel/testcases/spec-mode/argument.baseline.txt b/pkg/kernel/testcases/spec-mode/argument.baseline.txt
deleted file mode 100644
index 27c776c0b47008735d25cd7736deaa2fa478777f..0000000000000000000000000000000000000000
--- a/pkg/kernel/testcases/spec-mode/argument.baseline.txt
+++ /dev/null
@@ -1,37 +0,0 @@
-library;
-import self as self;
-import "dart:core" as core;
-
-abstract class Base extends core::Object {
-  constructor •() → void
-    : super core::Object::•()
-    ;
-}
-class Foo extends self::Base {
-  constructor •() → void
-    : super self::Base::•()
-    ;
-}
-class Bar extends self::Base {
-  constructor •() → void
-    : super self::Base::•()
-    ;
-}
-class Baz extends self::Base {
-  constructor •() → void
-    : super self::Base::•()
-    ;
-}
-static method foo(dynamic x) → void {}
-static method bar(dynamic x) → void {}
-static method foo_escaped(dynamic x) → void {}
-static method bar_escaped(dynamic x) → void {}
-static method escape(dynamic fn) → void {
-  fn.call(new self::Baz::•());
-}
-static method main() → dynamic {
-  self::foo(new self::Foo::•());
-  self::bar(new self::Bar::•());
-  self::escape(self::foo_escaped);
-  self::escape(self::bar_escaped);
-}