[Piglit] [PATCH] arb_gpu_shader5: Rename `signed` to `signed_`.

[Matt Turner]

On Sun, Mar 30, 2014 at 1:19 PM, Chris Forbes <chrisf at ijw.co.nz> wrote:
> nVIDIA's compiler considers `signed` to be a reserved word and so
> refuses to compile these shaders. Whether that's sensible or not,
> we'd like to see any real failures in these tests instead.

If you want to change it, change it to something sensible like "test_signed"