Merging r231423:

------------------------------------------------------------------------
r231423 | chaoren | 2015-03-05 18:22:54 -0500 (Thu, 05 Mar 2015) | 7 lines

Remove libedit and libncurses from LLDB_SYSTEM_LIBS if they're disabled.

Reviewers: clayborg, zturner, vharron, sbest

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D8065
------------------------------------------------------------------------

Differential Revision: http://reviews.llvm.org/D10323

llvm-svn: 240293