[Bug other/57195] Mode attributes with specific mode iterator can not be used as mode iterators in *.md files

[ubizjak at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57195

--- Comment #2 from Uros Bizjak <ubizjak at gmail dot com> ---
Created attachment 30084
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30084&action=edit
Proposed x86 patch that triggers the problem

Attached x86 patch triggers the problem, described in this PR.