patch 8.1.2175: meson files are not recognized

Problem:    Meson files are not recognized.
Solution:   Add the meson filetype. (Liam Beguin , Nirbheek Chauhan,
            closes #5056)  Also recognize hollywood.

runtime/filetype.vim

@@ -979,6 +979,9 @@ au BufNewFile,BufRead hg-editor-*.txt		setf hgcommit
 " Mercurial config (looks like generic config file)
 au BufNewFile,BufRead *.hgrc,*hgrc		setf cfg
 
+" Meson Build system config
+au BufNewFile,BufRead meson.build,meson_options.txt setf meson
+
 " Messages (logs mostly)
 au BufNewFile,BufRead */log/{auth,cron,daemon,debug,kern,lpr,mail,messages,news/news,syslog,user}{,.log,.err,.info,.warn,.crit,.notice}{,.[0-9]*,-[0-9]*} setf messages
 

src/testdir/test_filetype.vim

@@ -201,6 +201,7 @@ let s:filename_checks = {
     \ 'hex': ['file.hex', 'file.h32'],
     \ 'hgcommit': ['hg-editor-file.txt'],
     \ 'hog': ['file.hog', 'snort.conf', 'vision.conf'],
+    \ 'hollywood': ['file.hws'],
     \ 'hostconf': ['/etc/host.conf'],
     \ 'hostsaccess': ['/etc/hosts.allow', '/etc/hosts.deny'],
     \ 'template': ['file.tmpl'],
@@ -274,6 +275,7 @@ let s:filename_checks = {
     \ 'mason': ['file.mason', 'file.mhtml', 'file.comp'],
     \ 'master': ['file.mas', 'file.master'],
     \ 'mel': ['file.mel'],
+    \ 'meson': ['meson.build', 'meson_options.txt'],
     \ 'messages': ['/log/auth', '/log/cron', '/log/daemon', '/log/debug', '/log/kern', '/log/lpr', '/log/mail', '/log/messages', '/log/news/news', '/log/syslog', '/log/user',
     \     '/log/auth.log', '/log/cron.log', '/log/daemon.log', '/log/debug.log', '/log/kern.log', '/log/lpr.log', '/log/mail.log', '/log/messages.log', '/log/news/news.log', '/log/syslog.log', '/log/user.log',
     \     '/log/auth.err', '/log/cron.err', '/log/daemon.err', '/log/debug.err', '/log/kern.err', '/log/lpr.err', '/log/mail.err', '/log/messages.err', '/log/news/news.err', '/log/syslog.err', '/log/user.err',

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2175,
 /**/
     2174,
 /**/