LibJS: Eliminate some (unnecessary) Vector copies

Author: https://github.com/alimpfard
Commit: 699e1fdc07
Pull-request: https://github.com/SerenityOS/serenity/pull/3432
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/linusg ✅

Libraries/LibJS/Runtime/Exception.cpp

@@ -32,7 +32,7 @@ namespace JS {
 Exception::Exception(Value value)
     : m_value(value)
 {
-    auto call_stack = interpreter().call_stack();
+    auto& call_stack = interpreter().call_stack();
     for (ssize_t i = call_stack.size() - 1; i >= 0; --i) {
         auto function_name = call_stack[i].function_name;
         if (function_name.is_empty())