vim-patch:9.1.0279: filetype: roc files are not recognized

Problem:  filetype: roc files are not recognized
Solution: Detect '*.roc' files as roc filetype,
          add a basic filetype plugin (nat-418)

closes: vim/vim#14416

196b6678c5

Co-authored-by: nat-418 <93013864+nat-418@users.noreply.github.com>

test/old/testdir/test_filetype.vim

@@ -567,6 +567,7 @@ func s:GetFilenameChecks() abort
     \ 'rpgle': ['file.rpgle', 'file.rpgleinc'],
     \ 'robot': ['file.robot', 'file.resource'],
     \ 'robots': ['robots.txt'],
+    \ 'roc': ['file.roc'],
     \ 'ron': ['file.ron'],
     \ 'routeros': ['file.rsc'],
     \ 'rpcgen': ['file.x'],