Just to keep people up to date, attached is my current working diff on gcc (against gcc git of a few days ago)
It seems to work for the armv7 case; the testcases seem OK but I need to chat with some gcc people to see if the testcases are OK and I need to do a full native build and test. I'd expect it to need some more clean up yet, so don't panic over formatting etc.
libgcc fallbacks aren't done yet (but it will try and call libgcc).
Dave