patch 8.2.4790: lilypond filetype not recognized

Problem:    Lilypond filetype not recognized.
Solution:   Add patterns for lilypond. (Doug Kearns)

runtime/filetype.vim

@@ -1017,6 +1017,9 @@ au BufNewFile,BufRead *.ll			setf lifelines
 " Lilo: Linux loader
 au BufNewFile,BufRead lilo.conf			setf lilo
 
+" Lilypond
+au BufNewFile,BufRead *.ly,*.ily		setf lilypond
+
 " Lisp (*.el = ELisp, *.cl = Common Lisp)
 " *.jl was removed, it's also used for Julia, better skip than guess wrong.
 if has("fname_case")

src/testdir/test_filetype.vim

@@ -306,6 +306,7 @@ let s:filename_checks = {
     \ 'libao': ['/etc/libao.conf', '/.libao', 'any/.libao', 'any/etc/libao.conf'],
     \ 'lifelines': ['file.ll'],
     \ 'lilo': ['lilo.conf', 'lilo.conf-file'],
+    \ 'lilypond': ['file.ly', 'file.ily'],
     \ 'limits': ['/etc/limits', '/etc/anylimits.conf', '/etc/anylimits.d/file.conf', '/etc/limits.conf', '/etc/limits.d/file.conf', '/etc/some-limits.conf', '/etc/some-limits.d/file.conf', 'any/etc/limits', 'any/etc/limits.conf', 'any/etc/limits.d/file.conf', 'any/etc/some-limits.conf', 'any/etc/some-limits.d/file.conf'],
     \ 'liquid': ['file.liquid'],
     \ 'lisp': ['file.lsp', 'file.lisp', 'file.asd', 'file.el', 'file.cl', '.emacs', '.sawfishrc', 'sbclrc', '.sbclrc'],

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4790,
 /**/
     4789,
 /**/