patch 8.2.1044: not all systemd file types are recognized

Problem:    Not all systemd file types are recognized.
Solution:   Match several more files. (Guido Cella, closes #6319)

Author: brammool

runtime/filetype.vim

@@ -1655,8 +1655,9 @@ au BufNewFile,BufRead *.sil			setf sil
 au BufNewFile,BufRead */etc/sysctl.conf,*/etc/sysctl.d/*.conf	setf sysctl
 
 " Systemd unit files
-au BufNewFile,BufRead */systemd/*.{automount,mount,path,service,socket,swap,target,timer}	setf systemd
+au BufNewFile,BufRead */systemd/*.{automount,dnssd,link,mount,netdev,network,nspawn,path,service,slice,socket,swap,target,timer}	setf systemd
 " Systemd overrides
+au BufNewFile,BufRead */etc/systemd/*.conf.d/*.conf	setf systemd
 au BufNewFile,BufRead */etc/systemd/system/*.d/*.conf	setf systemd
 au BufNewFile,BufRead */.config/systemd/user/*.d/*.conf	setf systemd
 " Systemd temp files

src/testdir/test_filetype.vim

@@ -440,7 +440,7 @@ let s:filename_checks = {
     \ 'swiftgyb': ['file.swift.gyb'],
     \ 'sil': ['file.sil'],
     \ 'sysctl': ['/etc/sysctl.conf', '/etc/sysctl.d/file.conf'],
-    \ 'systemd': ['any/systemd/file.automount', 'any/systemd/file.mount', 'any/systemd/file.path', 'any/systemd/file.service', 'any/systemd/file.socket', 'any/systemd/file.swap', 'any/systemd/file.target', 'any/systemd/file.timer', '/etc/systemd/system/some.d/file.conf', '/etc/systemd/system/some.d/.#file', '/etc/systemd/system/.#otherfile', '/home/user/.config/systemd/user/some.d/mine.conf', '/home/user/.config/systemd/user/some.d/.#file', '/home/user/.config/systemd/user/.#otherfile'],
+    \ 'systemd': ['any/systemd/file.automount', 'any/systemd/file.dnssd', 'any/systemd/file.link', 'any/systemd/file.mount', 'any/systemd/file.netdev', 'any/systemd/file.network', 'any/systemd/file.nspawn', 'any/systemd/file.path', 'any/systemd/file.service', 'any/systemd/file.slice', 'any/systemd/file.socket', 'any/systemd/file.swap', 'any/systemd/file.target', 'any/systemd/file.timer', '/etc/systemd/some.conf.d/file.conf', '/etc/systemd/system/some.d/file.conf', '/etc/systemd/system/some.d/.#file', '/etc/systemd/system/.#otherfile', '/home/user/.config/systemd/user/some.d/mine.conf', '/home/user/.config/systemd/user/some.d/.#file', '/home/user/.config/systemd/user/.#otherfile'],
     \ 'systemverilog': ['file.sv', 'file.svh'],
     \ 'tags': ['tags'],
     \ 'tak': ['file.tak'],

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1044,
 /**/
     1043,
 /**/