This allows having exception cleanup code in binaries that don't
register their unwind tables.

2015-08-18  Max Filippov  <jcmvbkbc@gmail.com>
libgcc/
	* config/xtensa/t-windowed (LIB2ADDEH): Replace unwind-dw2-fde
	with unwind-dw2-fde-dip.

From-SVN: r226963