Replace deprecated LLVM functions.

[redstar]

Several functions regarding file handling are deprecated. This pull request replaces these functions with the new one from llvm::sys::fs and llvm::sys::path.

Please note that the call of llvm::sys::fs::exists() can be further simplified with the use of LLVM 3.0.

[dnadlinger]

Is there any benefit to merging this now? I'd rather wait a few days until LLVM 3.0 is out (and we have switched to it, but that should happen soon, as we are currently hitting a 2.9 regalloc bug on OS X), and then directly switch to the new, less messy, APIs.

[redstar]

Well, it is just a spin-off product of digging into LDC. No need to merge now...

[bioinfornatics]

Thanks a lot redstar
you are welcome

[redstar]

Ok, I got a LDC2 from the llvm3.0 branch. I redo the pull request for this branch soon.

[dnadlinger]

@redstar: That would be great (by the way, I hope my previous message didn't come off as rebuffing) – LLVM is going to be released on November 30th (actually, it should have been out in this week, but there were some last-minute issues and it collided with the LLVM conference). I'm currently preparing the DMD 2.056/LLVM 3.0 merge, and even just for eliminating the build warnings, it would be great to have this in.