Trilby [1] filed a deletion request for llvm37-split [2]:
A comment claimed this wouldn't build 1.5 years ago, and it's been
flagged out of date for almost a year with no action by the
maintainer.
Removal would keep the AUR tidy and save time of those who might
otherwise attempt to build this and fail.
[1] https://aur.archlinux.org/account/Trilby/
[2] https://aur.archlinux.org/pkgbase/llvm37-split/