lldb-6.0 build failure

[David]

I’m using a version of Apple’s clang that doesn’t support thread local storage 
(Apple LLVM version 7.0.2 (clang-700.1.81), from 2014). When I tried to install 
lldb-6.0 it failed because that compiler didn’t support thread local storage.

Is there a way to force the build for lldb-6.0 to use my installed clang 
(/opt/local/bin/clang-mp-6.0)? /opt/local/bin/clang points at this version.
My PATH is set to have /opt/local/bin prior to /usr/bin, so it wasn’t a PATH 
issue.

        David