patch 8.2.3603: fish filetype not recognized

Problem:    Fish filetype not recognized.
Solution:   Add a file pattern and match script line. (Doug Kearns)

runtime/filetype.vim

@@ -617,6 +617,9 @@ autocmd BufRead,BufNewFile *.fnl		setf fennel
 " Fetchmail RC file
 au BufNewFile,BufRead .fetchmailrc		setf fetchmail
 
+" Fish shell
+au BufNewFile,BufRead *.fish			setf fish
+
 " FlexWiki - disabled, because it has side effects when a .wiki file
 " is not actually FlexWiki
 "au BufNewFile,BufRead *.wiki			setf flexwiki

runtime/scripts.vim

@@ -194,6 +194,10 @@ if s:line1 =~# "^#!"
   elseif s:name =~# 'rsc\>'
     set ft=routeros
 
+    " Fish shell
+  elseif s:name =~# 'fish\>'
+    set ft=fish
+
   endif
   unlet s:name
 

src/testdir/test_filetype.vim

@@ -180,6 +180,7 @@ let s:filename_checks = {
     \ 'fennel': ['file.fnl'],
     \ 'fetchmail': ['.fetchmailrc'],
     \ 'fgl': ['file.4gl', 'file.4gh', 'file.m4gl'],
+    \ 'fish': ['file.fish'],
     \ 'focexec': ['file.fex', 'file.focexec'],
     \ 'forth': ['file.fs', 'file.ft', 'file.fth'],
     \ 'fortran': ['file.f', 'file.for', 'file.fortran', 'file.fpp', 'file.ftn', 'file.f77', 'file.f90', 'file.f95', 'file.f03', 'file.f08'],
@@ -662,6 +663,7 @@ let s:script_checks = {
       \ 'pascal': [['#!/path/instantfpc']],
       \ 'fennel': [['#!/path/fennel']],
       \ 'routeros': [['#!/path/rsc']],
+      \ 'fish': [['#!/path/fish']],
       \ }
 
 " Various forms of "env" optional arguments.

src/version.c

@@ -757,6 +757,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3603,
 /**/
     3602,
 /**/