chore(lp): don't use readdir_r on glibc
chore(lp): don't use readdir_r on glibc

glibc (unfortunately) deprecated readdir_r, as their readdir is already
reentrant. Future versions of POSIX will assume readdir is reentrant,
see https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html

dselsam/lean,dselsam/lean,johoelzl/lean,leanprover-community/lean,Kha/lean,avigad/lean,fpvandoorn/lean,digama0/lean,dselsam/lean,leanprover-community/lean,dselsam/lean,rlewis1988/lean,leodemoura/lean,leanprover/lean,johoelzl/lean,johoelzl/lean,leodemoura/lean,leodemoura/lean,rlewis1988/lean,avigad/lean,leodemoura/lean,Kha/lean,avigad/lean,rlewis1988/lean,dselsam/lean,fpvandoorn/lean,leanprover-community/lean,digama0/lean,Kha/lean,leodemoura/lean,fpvandoorn/lean,leodemoura/lean,avigad/lean,digama0/lean,Kha/lean,johoelzl/lean,dselsam/lean,rlewis1988/lean,leanprover-community/lean,Kha/lean,leanprover/lean,rlewis1988/lean,leanprover/lean,johoelzl/lean,fpvandoorn/lean,leanprover-community/lean,leanprover/lean,rlewis1988/lean,avigad/lean,digama0/lean,avigad/lean,leanprover/lean,digama0/lean,fpvandoorn/lean,Kha/lean,leanprover/lean,fpvandoorn/lean,leanprover-community/lean,digama0/lean,johoelzl/lean