patch 8.2.4664: Elvish files are not recognized

Problem:    Elvish files are not recognized.
Solution:   Recognize .elv files. (Bruno Roque, closes #10058)
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 0096f5f..4f0dbd7 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -168,6 +168,7 @@
     \ 'eelixir': ['file.eex', 'file.leex'],
     \ 'elm': ['file.elm'],
     \ 'elmfilt': ['filter-rules'],
+    \ 'elvish': ['file.elv'],
     \ 'epuppet': ['file.epp'],
     \ 'erlang': ['file.erl', 'file.hrl', 'file.yaws'],
     \ 'eruby': ['file.erb', 'file.rhtml'],
diff --git a/src/version.c b/src/version.c
index 72ba02c..bb5fc9d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4664,
+/**/
     4663,
 /**/
     4662,