define: DUK_USE_NONSTD_ARRAY_CONCAT_TRAILER
introduced: 1.0.0
removed: 2.3.0
default: true
tags:
  - ecmascript
  - compliance
description: >
  In ES5.1 trailing gaps of an argument array don't count towards the result
  length.  This is in essence a specification "bug" which was fixed in ES2015.
  This option was removed in 2.3.0, and the remaining behavior matches ES2015.