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

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 235faa3c3998dc1f9e22db7948927177d51abf92..1e6a92908261652e2ef82ac809f03146d2fdb93e 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1481,6 +1481,12 @@ Handle<Code> Factory::CopyCode(Handle<Code> code, Vector<byte> reloc_info) {
                      Code);
 }
 
+Handle<BytecodeArray> Factory::CopyBytecodeArray(
+    Handle<BytecodeArray> bytecode_array) {
+  CALL_HEAP_FUNCTION(isolate(),
+                     isolate()->heap()->CopyBytecodeArray(*bytecode_array),
+                     BytecodeArray);
+}
 
 Handle<JSObject> Factory::NewJSObject(Handle<JSFunction> constructor,
                                       PretenureFlag pretenure) {
@@ -2129,7 +2135,7 @@ Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
   share->set_instance_class_name(*Object_string());
   share->set_function_data(*undefined_value(), SKIP_WRITE_BARRIER);
   share->set_script(*undefined_value(), SKIP_WRITE_BARRIER);
-  share->set_debug_info(*undefined_value(), SKIP_WRITE_BARRIER);
+  share->set_debug_info(DebugInfo::uninitialized(), SKIP_WRITE_BARRIER);
   share->set_inferred_name(*empty_string(), SKIP_WRITE_BARRIER);
   StaticFeedbackVectorSpec empty_spec;
   Handle<TypeFeedbackMetadata> feedback_metadata =
@@ -2251,7 +2257,10 @@ Handle<DebugInfo> Factory::NewDebugInfo(Handle<SharedFunctionInfo> shared) {
       Handle<DebugInfo>::cast(NewStruct(DEBUG_INFO_TYPE));
   debug_info->set_shared(*shared);
   if (shared->HasBytecodeArray()) {
-    debug_info->set_abstract_code(AbstractCode::cast(shared->bytecode_array()));
+    // Create a copy for debugging.
+    Handle<BytecodeArray> original(shared->bytecode_array(), isolate());
+    Handle<BytecodeArray> copy = CopyBytecodeArray(original);
+    debug_info->set_abstract_code(AbstractCode::cast(*copy));
   } else {
     debug_info->set_abstract_code(AbstractCode::cast(shared->code()));
   }