patch 8.2.3599: not all gdbinit files are recognized

Problem:    Not all gdbinit files are recognized.
Solution:   Add "gdbinit". (Doug Kearns)
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index de2b0f2..90bc159 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -188,7 +188,7 @@
     \ 'freebasic': ['file.fb', 'file.bi'],
     \ 'fstab': ['fstab', 'mtab'],
     \ 'fvwm': ['/.fvwm/file', 'any/.fvwm/file'],
-    \ 'gdb': ['.gdbinit'],
+    \ 'gdb': ['.gdbinit', 'gdbinit'],
     \ 'gdmo': ['file.mo', 'file.gdmo'],
     \ 'gedcom': ['file.ged', 'lltxxxxx.txt', '/tmp/lltmp', '/tmp/lltmp-file', 'any/tmp/lltmp', 'any/tmp/lltmp-file'],
     \ 'gemtext': ['file.gmi', 'file.gemini'],
diff --git a/src/version.c b/src/version.c
index 7cffc01..cb1599d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3599,
+/**/
     3598,
 /**/
     3597,