Homebrew/homebrew — pull request #29976 by mcuelenaere (2014-06-08 15:13:45+00:00)
Title: Fix LLVM CMake modules not being preprocessed

The CMake modules bundled with LLVM need to be preprocessed before being
installed. This can only be done by doing a CMake build.

Ideally, CMake is used to build LLVM but this should work fine as a workaround.