egcs-1.1 binary incompatibility

["James R. Van Zandt" <jrv@vanzandt.mv.com>]

At the egcs web site (http://egcs.cygnus.com), I ran across this
caveat:

   egcs-1.1 compiled C++ code is not binary compatible with egcs-1.0.x
   or gcc-2.8.x due to changes necessary to support thread safe
   exception handling.

We need to find out *exactly* what this means before we start using it
to build packages.  Do we need to recompile shared libraries to work
with new programs, or vice-versa?  How about static libraries?  

Will we have to introduce new .so numbers for libraries so we can
support a mixture of packages compiled with new and old compilers?

			      - Jim Van Zandt