Summary:
Previously, the installation path was simply '/'.
Using '/usr/local' would ensure that LLVM installation does not
conflict with software installed via package managers.
Reviewers: mehdi_amini, klimek
Reviewed By: klimek
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37213
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311890 91177308-0d34-0410-b5e6-96231b3b80d8