Bootstrap broken with checking disabled on at least i686

[Dan Nicolaescu]

Steven Bosscher <stevenb@suse.de> writes:

  > Bootstrap comparison failure!
  > ./alias.o differs
  > ./alloc-pool.o differs

I see the same thing on both i686-linux and x86_64-linux.
The bootstrap worked Monday 1pm PDT.

All the differences reported are due to debug info. After stripping
all the object files make compare is happy.

Recompiling stage2 dwarf2*.o with the stage1 compiler without
optimization solves the problem.