[Bug target/25967] Add attribute naked for x86

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25967

--- Comment #13 from Uroš Bizjak <ubizjak at gmail dot com> ---
Created attachment 41862
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41862&action=edit
Patch that implements naked attribute