[Bug bootstrap/17817] [4.0 Regression] restage[1,2,3] and then bootstrap no longer cause build dir to be rebuilt

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|restage[1,2,3] and then     |[4.0 Regression]
                   |bootstrap no longer cause   |restage[1,2,3] and then
                   |build dir to be rebuilt     |bootstrap no longer cause
                   |                            |build dir to be rebuilt


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17817