971031 to 971105 negative enhancement

[Jeffrey A Law]

  In message < 199711071410.OAA01262@galileo.msi-uk.com >you write:
  > hello there,
  > 
  > The following source code used to compile ok on 971031
[ ... ]

  > but on 971105 it crashes the compiler, around line 2078 of gcc/except.c
Looks like the same problem HJ is having with sjlj exceptions; the
EH regions are not nested.

971031 didn't use EH regions for sjlj exceptions, so it's unclear if
971031 worked by accident (since it never checked that EH regions were
nested) or by designed (I screwed up with the EH region annotations)

I'm working on it.
jeff