[Bug tree-optimization/63748] [4.9/5 Regression] wrong may be used uninitialized warning (abnormal edges)

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63748

--- Comment #8 from Alan Modra <amodra at gmail dot com> ---
Thanks!  Fix confirmed with gdb sources prior to the workaround Uli committed. 
Is the fix appropriate for gcc-4.9?  If not, I'll be happy to adjust the target
milestone and close the bug.