"Fix LWP" patch breaks bootstrap on i686-pc-linux-gnu

[Jason Merrill]

This patch went in today, but I don't see any mail on gcc-patches about 
it.  i386.c fails to build on i686-pc-linux-gnu, with the compiler 
complaining about a duplicate case label in

               case CODE_FOR_lwp_lwpvalsi3:
               case CODE_FOR_lwp_lwpvaldi3:
               case CODE_FOR_lwp_lwpinssi3:
               case CODE_FOR_lwp_lwpinsdi3:

Jason