Move kernel baseline tests to front_end.

pkg/kernel/testcases/spec-mode/void-methods.baseline.txt

Index: pkg/kernel/testcases/spec-mode/void-methods.baseline.txt
diff --git a/pkg/kernel/testcases/spec-mode/void-methods.baseline.txt b/pkg/kernel/testcases/spec-mode/void-methods.baseline.txt
deleted file mode 100644
index e0dc634666252499a95fbdf2f07949aae8e01fd7..0000000000000000000000000000000000000000
--- a/pkg/kernel/testcases/spec-mode/void-methods.baseline.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-library;
-import self as self;
-import "dart:core" as core;
-
-class Foo extends core::Object {
-  field core::List<dynamic> list = <dynamic>[1, 2, 3];
-  constructor •() → void
-    : super core::Object::•()
-    ;
-  set first(dynamic x) → dynamic
-    this.list.[]=(0, x);
-  operator []=(dynamic x, dynamic y) → dynamic
-    this.list.[]=(x, y);
-  method clear() → void
-    return this.list.clear();
-}
-static method main() → dynamic {
-  new self::Foo::•().first = 4;
-  new self::Foo::•().[]=(3, 4);
-  new self::Foo::•().clear();
-}