[Patch,ld] Fix check_lto_available

[nick clifton]

Hi Vidya,
> ld/testsuite/ChangeLog:
>
> 2013-12-11  Vidya Praveen  <vidyapraveen@arm.com>
>
> 	* lib/ld-lib.exp (check_lto_available): Support cflags,ldflags and
> 	test by compiling for an executable rather than shared library.

Approved - please apply.

Cheers
   Nick