An overhaul of the exception handling code. This is arguably more correct than

what was there before. In "no FP mode", we weren't generating labels and unwind
table entries after each "push" instruction. While more than likely "okay", it's
not technically correct. The major thing was that the ordering of when to define
a new CFA register and at what offset wasn't correct. This would cause the
exception handling to fail in ways most miserable to users.

I also cleaned up some code a bit. There's one function which has a "return" at
the beginning, so it's never used. Should I just remove it? :-)

llvm-svn: 79139