[debugger] implement per-function code coverage.

test/debugger/debug/debug-scripts-throw.js

Index: test/debugger/debug/debug-scripts-throw.js
diff --git a/test/debugger/debug/debug-scripts-throw.js b/test/debugger/debug/debug-scripts-throw.js
deleted file mode 100644
index e703f49054350fb6972ea7a3a65622617dbc499c..0000000000000000000000000000000000000000
--- a/test/debugger/debug/debug-scripts-throw.js
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-
-Debug = debug.Debug;
-
-Debug.disable();
-assertThrows("Debug.scripts()");
-
-Debug.enable();
-assertDoesNotThrow("Debug.scripts()");