為什麼大家都開始惡搞版號了呢…
LLVM 4.0.0 Release Notes — LLVM 4 documentation
"Starting with this release, LLVM is using a new versioning scheme, increasing the major version number with each major release. Stable updates to this release will be versioned 4.0.x, and the next major release, six months from now, will be version 5.0.0."