BOOTSTRAP FAIL in loop.c on powerpc-unknown-linux-gnu

[David Edelsohn]

>>>>> Franz Sirl writes:

Franz> the current mainline won't bootstrap on powerpc-unknown-linux-gnu,
Franz> compilation fails in stage1/libgcc2/_bb. Here's the output of the gdb
Franz> session, it probably segfaults because of loop_iteration_var is 0.

	I have added an additional test to ensure that loop_iteration_var
is non-zero before use.  That should solve this failure although I am not
sure why it did not appear when I was bootstrapping.

David