No OS X support

[alejandrojapkin]

Please beware that pytorch (CUDA torch) for OS X has serious issues building some of which have been assigned wrong workarounds that don't solve the issue, so warp-CTC cannot be currently and successfully built with the required CUDA support on native OS X. There's no clear addressing of this problem.

Building Pytorch I have tried all plausible downgrades of the xcode CLI and none work as it's claimed that X.XX or Y.YY version work in different repos; this "fix" was probably not a fix at all, e.g. not what made the code eventually build for the test case. This is a seriously overlooked nvidia/xcode compatibility issue I've seen in other related repos, claiming the "fix" to be in another CLI version which doesn't actually work either. Specifically with the 8.2 CLI (documented as "working"):

clang --version Apple LLVM version 8.0.0 (clang-800.0.42.1) Target: x86_64-apple-darwin16.7.0 Thread model: posix InstalledDir: /Library/Developer/CommandLineTools/usr/bin

Errors: nvcc fatal : The version ('80000') of the host compiler ('Apple clang') is not supported ... CMake Error at ATen_generated_THCStorageCopy.cu.o.cmake:207 (message): ... etc.