fix spec function evaluations part of an outer string construction

[Joseph S. Myers]

On Thu, 3 May 2012, Olivier Hainque wrote:

> 2012-05-03  Olivier Hainque  <hainque@adacore.com>
> 
> 	* gcc.c (eval_spec_function): Finalize/restore the current string
> 	obstack state as part of the context push/pop operations.

OK.

-- 
Joseph S. Myers
joseph@codesourcery.com