[inspector] fix positions for single expression arrow function

src/full-codegen/full-codegen.cc

Index: src/full-codegen/full-codegen.cc
diff --git a/src/full-codegen/full-codegen.cc b/src/full-codegen/full-codegen.cc
index cd32c4db21df55080243eae3d419a9436fb8c5f6..262620b83064ee0f83447192d5d7510dca1b4425 100644
--- a/src/full-codegen/full-codegen.cc
+++ b/src/full-codegen/full-codegen.cc
@@ -682,8 +682,7 @@ void FullCodeGenerator::SetFunctionPosition(FunctionLiteral* fun) {
 void FullCodeGenerator::SetReturnPosition(FunctionLiteral* fun) {
   // For default constructors, start position equals end position, and there
   // is no source code besides the class literal.
-  int pos = std::max(fun->start_position(), fun->end_position() - 1);
-  RecordStatementPosition(pos);
+  RecordStatementPosition(fun->return_position());
   if (info_->is_debug()) {
     // Always emit a debug break slot before a return.
     DebugCodegen::GenerateSlot(masm_, RelocInfo::DEBUG_BREAK_SLOT_AT_RETURN);