[libcxxabi][PATCH] use return address register from CIE

[Nick Kledzik]

On Apr 24, 2014, at 8:35 PM, Chris Lattner wrote:
> On Apr 24, 2014, at 6:55 PM, Nick Kledzik <kledzik at apple.com> wrote:
> 
>> I got a bug report that the unwinder is not using the return_address_register value in the CIE.  This patch fixes that.  Instead of hard coding which psudeo register number contains the saved return address in the stack frame, the register number is found in the CIE.  This allowed a bunch of template specializations to be removed.
>> 
>> Tested on Mac OS X 10.9 by running the test suite with OPTIONS:
>> -mmacosx-version-min-10.5 -Wl,-no_compact_unwind
>> which disables compact unwind and runs with just dwarf unwind info.
> 
> Given that you're the author of this code, you're the best person to review this.  Are you asking for some specific testing on another platform?

Just playing nice  :-)   Someone might be working on this same area and I want to see if there are any variations that might make the patch better.

-Nick