The Washington Post commemorated the anniversary of the speech in an editorial Friday, adding the "ash heap of history" phrase was one Reagan personally wrote into the address, according to Reagan at Westminster: Foreshadowing the End of the Cold War(TAMU Press, 2011).
Read more here.
http://www.washingtonpost.com/opinions/ronald-reagan-and-the-power-to-change-history/2012/06/07/gJQAQI9VLV_story.html