[libcxx] Add "install-libcxx" target.

Summary: Currently you can't install libc++ from within the LLVM tree without installing all of LLVM. This patch adds an install rule for libc++.

Reviewers: mclow.lists, danalbert, jroelofs, EricWF

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11697

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245470 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed