[PATCH] assert.h: allow gcc to detect assert(a = 1) errors

[Joseph Myers]

On Wed, 23 Nov 2016, Zack Weinberg wrote:

> ... Would you please file a feature-request with the gcc people asking
> for something that turns __extension__ back off?  It would be nice to

(Which I suggested in <https://gcc.gnu.org/ml/gcc/2001-04/msg00642.html> - 
note the point about counting nesting so this cancels exactly one 
enclosing __extension__.)

-- 
Joseph S. Myers
joseph@codesourcery.com