[es8] More spec compliant syntactic tail calls implementation.

test/message/syntactic-tail-call-in-extends.js

Index: test/message/syntactic-tail-call-in-extends.js
diff --git a/test/message/syntactic-tail-call-in-try.js b/test/message/syntactic-tail-call-in-extends.js
similarity index 73%
copy from test/message/syntactic-tail-call-in-try.js
copy to test/message/syntactic-tail-call-in-extends.js
index 97eb4f757ab27e898e888078a46b80a8df61097a..02b578d4ca1a301ea7f39e814ea0d25924c16224 100644
--- a/test/message/syntactic-tail-call-in-try.js
+++ b/test/message/syntactic-tail-call-in-extends.js
@@ -4,13 +4,6 @@
 
 // Flags: --harmony-explicit-tailcalls
 
-function f() {
-  return 1;
-}
-
 function g() {
-  try {
-    return continue f();
-  } catch(e) {
-  }
+  return class A extends continue f() {};
 }