Fix problem with constant modulus

[John David Anglin]

> Your patch causes a bootstrap failure on AIX when GCC is invokved
> with -mcpu=power option to produce POWER architecture output.  The failure
> occurs when compiling locale-inst.cc:

The patch also causes a bootstrap failure on hppa-unknown-linux-gnu
building ada.  See PR optimization/15028.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)