Bug#811707: FTBFS with GCC 6: compiler failed the ACC conformance test

[Matthias Klose <doko@debian.org>]

Control: reassign -1 src:ucl

both gcc-5 and gcc-6 show the same error message:

$ gcc-6 -c test.c
test.c:1:12: error: size of array '__acc_cta' is negative
 extern int __acc_cta[1-2*!((1l << (8*4 -1)) < 0)];
            ^~~~~~~~~