MFC r355948:
Bootstrap mergeinfo for contrib/llvm-project
Merge (record-only) the following paths to contrib/llvm-project:
- ^/vendor/llvm-project/master
- ^/vendor/llvm-project/release-8.x
- ^/vendor/llvm-project/release-9.x
MFC r355951:
Merge empty dir updates from r355950 in vendor/llvm-project.
MFC r355957:
Merge diff elimination updates from r355953 into vendor/llvm-project.
MFC r355959:
Consolidate FREEBSD-Xlist files of different llvm sub-projects into one.