Include platform agnostic <HostGetOpt.h> in the place of <getopt.h>

Summary: Problem caught on NetBSD with missing getopt_long_only(3).

Change by Kamil Rytarowski <n54@gmx.com>

Reviewers: joerg, brucem

Subscribers: brucem, lldb-commits

Differential Revision: http://reviews.llvm.org/D12748

llvm-svn: 248990