Setting -DGCC_INSTALL_PREFIX causes tests to fail

[Dmitri Gribenko]

On Sat, Apr 6, 2013 at 12:19 AM, Dmitri Gribenko <gribozavr at gmail.com> wrote:
> Setting -DGCC_INSTALL_PREFIX causes tests to fail.

The attached patch unbreaks all tests except Hexagon, because it uses
a different codepath.  But the patch feels like a workaround to me,
rather than a solution.  Please take a look.  It causes clang to
forget about GCC_INSTALL_PREFIX if there's -sysroot or
-ccc-install-dir.

Dmitri

--
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/