Add AIX support to Path.inc, Host.h, and CMake.

Patch by Andrew Paprocki!

Differential Revision: https://reviews.llvm.org/D18359

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276045 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed