[Upstream] Detects whether RESOURCE_TYPE_IO is defined.

Summary: This fixes lldb build on macOS SDK prior to 10.12.

Reviewers: JDevlieghere

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D66034

Change-Id: I89f69fdf75d169fa887c8c31501b4cc5793c0bc8
llvm-svn: 368496