[interpreter, debugger] support debug breaks via bytecode array copy

src/runtime/runtime-debug.cc

Index: src/runtime/runtime-debug.cc
diff --git a/src/runtime/runtime-debug.cc b/src/runtime/runtime-debug.cc
index 2dfdc1bc72d7843ae345773ff3f9c8a508ddd0fe..c29ea9a35d5e7379fff5b567cce19d1167f614a8 100644
--- a/src/runtime/runtime-debug.cc
+++ b/src/runtime/runtime-debug.cc
@@ -22,8 +22,7 @@ RUNTIME_FUNCTION(Runtime_DebugBreak) {
   // Get the top-most JavaScript frame.
   JavaScriptFrameIterator it(isolate);
   isolate->debug()->Break(args, it.frame());
-  isolate->debug()->SetAfterBreakTarget(it.frame());
-  return isolate->heap()->undefined_value();
+  return isolate->debug()->SetAfterBreakTarget(it.frame());
 }