[Bug target/29997] various targets: GCC fails to encode epilogues in unwind-info

[ian at airs dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29997

--- Comment #6 from Ian Lance Taylor <ian at airs dot com> ---
All the insns in sh_expand_epilogue need to be examined to see if they need
REG_CFA notes.  Some of them already have them.  I don't know what more are
needed.

For example, look at the changes made to the i386 backend when rth added the
general support for unwinding through epilogues:
http://gcc.gnu.org/ml/gcc-patches/2009-05/msg00277.html