Install CentOS SCLo RH Testing repository:

yum install centos-release-scl-rh

Install llvm-toolset-7-lldb rpm package:

yum --enablerepo=centos-sclo-rh-testing install llvm-toolset-7-lldb

参考链接：
https://centos.pkgs.org/7/centos-sclo-rh-testing/llvm-toolset-7-lldb-4.0.1-5.el7.x86_64.rpm.html
https://zhuanlan.zhihu.com/p/40780819