[Bug c/65455] typeof _Atomic fails

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65455

--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
By design, typeof removes qualifiers in certain cases.  Currently it only 
removes them from atomic types (as needed for use in <stdatomic.h>), but 
arguably it should do so more generally - this would be useful for certain 
macros when passed const arguments, and would reflect that qualifiers on 
rvalues are not meaningful in C standard terms (so rvalues should always 
be considered to have unqualified type) but GCC's internal representation 
may or may not have them.

      /* For use in macros such as those in <stdatomic.h>, remove all
         qualifiers from atomic types.  (const can be an issue for more macros
         using typeof than just the <stdatomic.h> ones.)  */