r231245 - Adjust the changes from r230255 to bail out if the backend can't lower

[Joerg Sonnenberger]

On Thu, Mar 05, 2015 at 11:38:28AM +0000, Renato Golin wrote:
> Well, we're now getting a different error, during the compilation phase...
> 
> http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-full/builds/4064/steps/ninja%20check%201/logs/stdio
> 
> and it seems to be related to this very problem. Any idea on how to fix that?

That looks exactly like the thing this commit is supposed to catch. If
it works, it is only by accident when the function already has landing
pads AND the target is iOSish.

Joerg