Redhat has had llvm-toolset-7.0 available since March 2019. It adds support for clang and llvm version 7. See https://developers.redhat.com/blog/2019 ... rust-1-31/

Is this going to be available on Centos 7 and if so, when?

Don't confuse this with llvm-toolset-7 which supports the older clang version 5 which is already available with Centos 7.