Adding a syntax group to ALL syntaxes

I want to add a syntax group to all syntaxes. Namely, I want to highlight characters like +,-,*,/ and other punctuation chars for every programming language. I know that I can add a <language>.vim file for every language to my .vim/after/syntax folder, but I want to make this generic. Currently I have to create one such (exactly the same) syntax addendum file for every programming language, and that's... inelegant.

Basically I'd like to place an all.vim file in .vim/after/syntax and have the contents of that file added to every syntax file. I'm fairly sure that this option doesn't exist (I checked the vim docs), so I'm looking for some way to emulate that. Is there perhaps a program开发者_如何学Gomatic way of adding the new syntax group to every syntax?

You could simply place it in your vimrc.