[Bug preprocessor/60304] Including <atomic> disables -Wconversion-null

[bug-reports at psdtechnologies dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60304

--- Comment #1 from bug-reports at psdtechnologies dot com ---
Created attachment 32191
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32191&action=edit
Similar code behaving as expected