[PATCH] Support invoking the patchpoint intrinsic

[Andrew Trick]

I think patching an exception throwing call is valid. You can certainly have an inline cache to an exception throwing method.

I also think it's valid to use the platform's exception handling support, although probably not performant if your app throws exceptions. As Filip mentioned, the best approach is to profile the throws, deoptimize when they aren't expected and emit branches when they are.

Anyway, great work. Please add tests and cleanup the code as you mentioned.

http://reviews.llvm.org/D5572