[llvm] r219575 - AssumptionTracker: Don't create temporary CallbackVHs.

[Philip Reames]

Ben,

Could you give a bit of context on this change for those of us 
unfamiliar with the issue?  I don't understand why the new code is 
advantageous.

On 10/11/2014 12:13 PM, Benjamin Kramer wrote:
> -  CachedAssumeCalls.erase(F);
> +  auto I = CachedAssumeCalls.find_as(F);
> +  if (I != CachedAssumeCalls.end())
> +    CachedAssumeCalls.erase(I);
>   }
This particular part seems ugly.  What's the semantic difference here?  
Why is this better?  If it's better, why isn't it simply part of the 
standard erase routine?

Philip