AIX exception-handling vs. builtin_return_address

[Mark Mitchell]

David, Franz --

  Thanks for confirming my analysis and for the patch. 

  I'm going to try Franz's patch; it seems to make sense to check
rs6000_current_abi, rather than DEFAULT_ABI.  (Other than that,
they're very similar.)

  I'll let y'all know how that goes, but I have hopes for the day!

--
Mark Mitchell                   mark@codesourcery.com
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