[clang] [clang-format] Add SpaceInParensOption for __attribute__ keyword (PR #77522)

[Gedare Bloom via cfe-commits]

gedare wrote:

> This is migrated from Phabricator, see more discussion there. I will next provide an option for SpacesInParensOptions.Doubled to control (and override) injection of spaces within doubled parens `(( ))`.

Actually, spaces in double parens might not work out well. It will not allow separation of multiple parens in some contexts such as conditional blocks or function calls. It may be better to provide a sub-option to this `InAttributeSpecifiers` instead.


https://github.com/llvm/llvm-project/pull/77522