[clang] [polly] [clang-format] Add AllowShortType option for AlwaysBreakAfterReturnType. (PR #78011)

[via llvm-commits]

rmarker wrote:

Updated FormatTests to account for the change to the style.
(Forgetting them is what I get for coding late).

This should help when evaluating the scope of the change.

https://github.com/llvm/llvm-project/pull/78011