Debugger: use debug break slots to break at function exit.

test/cctest/test-debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 394 matching lines @@
   HeapIterator iterator(CcTest::heap());
   for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
     CHECK(!obj->IsDebugInfo());
     CHECK(!obj->IsBreakPointInfo());
 
     // If deep check of functions is requested check that no debug break code
     // is left in all functions.
     if (check_functions) {
       if (obj->IsJSFunction()) {
         JSFunction* fun = JSFunction::cast(obj);
-        for (RelocIterator it(fun->shared()->code()); !it.done(); it.next()) {
-          RelocInfo::Mode rmode = it.rinfo()->rmode();
-          if (RelocInfo::IsCodeTarget(rmode)) {
-            CHECK(!Debug::IsDebugBreak(it.rinfo()->target_address()));
-          } else if (RelocInfo::IsJSReturn(rmode)) {
-            CHECK(!it.rinfo()->IsPatchedReturnSequence());
-          }
+        for (RelocIterator it(fun->shared()->code(),
+                              RelocInfo::kDebugBreakSlotMask);
+             !it.done(); it.next()) {
+          CHECK(!it.rinfo()->IsPatchedDebugBreakSlotSequence());
         }
       }
     }
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
@@ skipping 7143 matching lines @@
       "let y = 2;               \n"
       "debugger;                \n"
       "x * y",
       30);
   ExpectInt32(
       "x = 1; y = 2; \n"
       "debugger;"
       "x * y",
       30);
 }