release_33 branch: proposing r183984

[Tom Stellard]

Hi Anton,

Is this patch OK to merge to the 3.3 branch?

On Mon, Jul 08, 2013 at 09:55:16PM +0200, Dimitry Andric wrote:
> Hi,
> 
> For the 3.3 release branch, I would like to propose merging r183984:
> 
> r183984 from llvm trunk (by Derek Schuff):
> 
>   Make PrologEpilogInserter save/restore all callee saved registers in
>   functions which call __builtin_unwind_init()
> 
>   __builtin_unwind_init() is an undocumented gcc intrinsic which has
>   this effect, and is used in libgcc_eh.
> 
>   Goes part of the way toward fixing PR8541.
> 
> It obsoletes the ugly hack we had to do in FreeBSD to libgcc's unwind code to work around very tricky crash problems (see http://svnweb.freebsd.org/changeset/base/245272 ), and should also work for arches other than x86_64.
> 
> This commit should apply to the release_33 branch without modification.
> 
> -Dimitry
>