[clang] [Clang][DLCov][NFCish] Fix debugloc coverage tracking macro in Clang (PR #146521)

[Orlando Cazalet-Hyams via cfe-commits]

https://github.com/OCHyams commented:

Can you explain how the include helps in a bit more detail? I don't see what it adds (I'm not very familiar with llvm-config!)

https://github.com/llvm/llvm-project/pull/146521