(followup) reload_combine bug fix

[Christian BRUEL]

I analyzed a bug (recorded bugzilla #30807) until I found it seemed 
similar to a one already reported in

http://gcc.gnu.org/ml/gcc-patches/2006-01/msg01395.html

Unfortunalty there was no testcase because difficult to isolate. Gladly 
the one I analyzed is smaller and more manageable, testcase appended in 
bugzilla #30807.

The analysis for this bug looks similar to Joern's, confirming this can 
be a generic also existing in trunk, although it is only noticed on sh.

thanks,

-c