[patch] Only build personality routine for SymbianOS.

[Benjamin Kosnik]

> The problem is that for eh_personality.cc we really do want to share
> most of the code.  

Not convinced. Lines 90-315 are all arm, IMHO the personality function
could be better modularized with hooks for sjlj_exceptions,
callframe_exceptions, and arm_exceptions. I think there is a better way
to do this than you are proposing.

Sorry I'm vague on the details.

> > 1) LIBSUPCXX_PRONLY should be LIBSUPCXX_PERSONALITY_ONLY
> > 2) edit Makefile.am not include/Makefile.am to not install the include files
> > 3) with the changes above, you can use host_sources to do the libsupc++/Makefile.am bits

Also please spell check the comments for typos. I will check in a fix
for the current bits. 

> I've leave it to you and Paul to agree on a particular plan.  Is 3) as a
> pre-checkin requirement, or is that something that could be done as a
> subsequent cleanup?

I feel like if it's left for cleanup, it will never happen. 

-benjamin