3.6.1 Nomination: r232438, r232443, and clang/r232439, which fix pr22436

[Tom Stellard]

Hi Justin,

I've merged these patches:

On Wed, Apr 29, 2015 at 10:00:15AM -0700, Justin Bogner wrote:
> Hey Tom, can you cherry pick these three patches, which collectively fix
> llvm.org/pr22436, to the 3.6 branch? I'm the code owner for profiling
> and coverage instrumentation and this is a pretty straightforward bug
> fix.
> 
>   llvm/r232438:

r236303

> 
>     GCOV: Make the exit block placement from r223193 optional
>     
>     By default we want our gcov emission to stay 4.2 compatible, which
>     means we need to continue emit the exit block last by default. We add
>     an option to emit it before the body for users that need it.
> 
>   llvm/r232443:

r236304

> 
>     llvm-cov: Warn instead of error if a .gcda has arcs from an exit block
>     
>     Patch by Vanderson M. Rosario. Thanks!
> 
>   clang/r232439:

r236305

> 
>     GCOV: Expose the -coverage-exit-block-before-body flag in clang -cc1
>     
>     This exposes the optional exit block placement logic from r232438 as a
>     clang -cc1 option. There is a test on the llvm side, but there isn't
>     really a way to inspect the gcov options from clang to test it here as
>     well.

-Tom