Build SH backtrace with -funwind-tables

[Kaz Kojima]

"Joseph S. Myers" <joseph@codesourcery.com> wrote:
> When I made SH backtrace use unwind tables
> <http://sourceware.org/ml/libc-alpha/2011-12/msg00000.html>, I forgot
> to include the sysdeps/sh/Makefile change to build the backtrace
> implementation with -funwind-tables - needed if the compiler used to
> build glibc doesn't default to unwind tables, so that the backtrace
> function can backtrace out of itself and into the user program.  This
> patch adds the missing makefile change.

Looks fine to me.  Thanks!

Regards,
	kaz