changed hash value calculation.

func name changed from hashValue() to hashIndex().  the
func really calculated a index anyway.
changed hash func impl.  essentually it was calculating a hash value
from a hash value.  this is a implementation thing.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@66 138bc75d-0d04-0410-961f-82ee72b054a4