MFH: r504435 r504436

Fix a bug when ${PREFIX} != /usr/local.[0]

As of LLVM 8.0.1, pre-releases have moved to github. Chase this change.

PR: 238603 [0]
Submitted by: mi [0]

Revert accidental update to distinfo.

Reported by: Christoph Moench-Tegeder <cmt@burggraben.net>

Approved by: portmgr (blanket fixes)