patch 8.2.3679: objc file detected as Octave

Problem:    objc file detected as Octave. (Antony Lee)
Solution:   Detect objc by preprocessor lines. (Doug Kearns, closes #9223,
            closes #9220)
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 6134b32..81ddbe9 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -891,6 +891,16 @@
   call assert_equal('objc', &filetype)
   bwipe!
 
+  call writefile(['#include <header.h>'], 'Xfile.m')
+  split Xfile.m
+  call assert_equal('objc', &filetype)
+  bwipe!
+
+  call writefile(['#define FORTY_TWO'], 'Xfile.m')
+  split Xfile.m
+  call assert_equal('objc', &filetype)
+  bwipe!
+
   " Octave
 
   call writefile(['# Octave line comment'], 'Xfile.m')
diff --git a/src/version.c b/src/version.c
index b7a93ed..ca0f16f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3679,
+/**/
     3678,
 /**/
     3677,