vim-patch:9.0.0562: HSL playlist files are not recognized (#20307)

Problem:    HSL playlist files are not recognized.
Solution:   Add a pattern to recognize HSL palylist files. (Benoît Ryder,
            closes vim/vim#11204)
35fdd9a67d

src/nvim/testdir/test_filetype.vim

@@ -255,6 +255,7 @@ let s:filename_checks = {
     \ 'hex': ['file.hex', 'file.h32'],
     \ 'hgcommit': ['hg-editor-file.txt'],
     \ 'hjson': ['file.hjson'],
+    \ 'hlsplaylist': ['file.m3u8'],
     \ 'hog': ['file.hog', 'snort.conf', 'vision.conf'],
     \ 'hollywood': ['file.hws'],
     \ 'hoon': ['file.hoon'],