patch 8.2.2773: PSL filetype not recognized

Problem:    PSL filetype not recognized.
Solution:   Add a filetype pattern. (Daniel Kho, closes #8117)

runtime/filetype.vim

@@ -1342,6 +1342,9 @@ au BufNewFile,BufRead *.pdb			setf prolog
 " Promela
 au BufNewFile,BufRead *.pml			setf promela
 
+" Property Specification Language (PSL)
+au BufNewFile,BufRead *.psl			setf psl
+
 " Google protocol buffers
 au BufNewFile,BufRead *.proto			setf proto
 au BufNewFile,BufRead *.pbtxt			setf pbtxt

src/testdir/test_filetype.vim

@@ -392,6 +392,7 @@ let s:filename_checks = {
     \ 'ps1': ['file.ps1', 'file.psd1', 'file.psm1', 'file.pssc'],
     \ 'ps1xml': ['file.ps1xml'],
     \ 'psf': ['file.psf'],
+    \ 'psl': ['file.psl'],
     \ 'puppet': ['file.pp'],
     \ 'pyrex': ['file.pyx', 'file.pxd'],
     \ 'python': ['file.py', 'file.pyw', '.pythonstartup', '.pythonrc', 'file.ptl', 'file.pyi', 'SConstruct'],

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2773,
 /**/
     2772,
 /**/