Regression on mainline in tree-vrp.c

[Kazu Hirata]

Hi Rainer and Steve,

> | 4.1.0 20050419 (experimental) (i386-pc-solaris2.10) GCC error:           |
> | in set_value_range, at tree-vrp.c:124                                    |
> | Error detected at sem_intr.adb:437:1                                     |

There seem to be several ways to get to this ICE.  set_value_range is
used in many places in tree-vrp.c.  I'll try to take a look at these
in the next few days.

Kazu Hirata