[lanai] Make Lanai backend non-experimental

Summary:
Add Lanai backend to default targets.

Discussion of proposal: http://lists.llvm.org/pipermail/llvm-dev/2016-July/102480.html. ISA added in r279149.

Reviewers: jyknight, rengolin, eliben, chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22530

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279498 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed