Add st[pr]ncpy to stmt_kills_ref_p

[Richard Biener]

On April 29, 2017 9:17:12 AM GMT+02:00, Marc Glisse <marc.glisse@inria.fr> wrote:
>Hello,
>
>this patch seems rather trivial, once one knows that those functions 
>always write exactly n characters (they fill with 0 as needed at the
>end).
>
>Bootstrap+regtest on powerpc64le-unknown-linux-gnu.

OK.

Richard.

>2017-05-02  Marc Glisse  <marc.glisse@inria.fr>
>
> 	PR tree-optimization/80487
>gcc/
> 	* tree-ssa-alias.c (stmt_kills_ref_p): Handle stpncpy and strncpy.
>
>gcc/testsuite/
> 	* gcc.dg/tree-ssa/strncpy-1.c: New file.