[clang] [clang-format] Add ObjCSpaceBeforeMethodDeclColon option to control space before Objective-C method return type (PR #170579)

[Björn Schäpers via cfe-commits]

HazardyKnusperkeks wrote:

> > Please link a public style guide that wants no space after the +/- prefix. See https://clang.llvm.org/docs/ClangFormatStyleOptions.html#adding-additional-style-options. Also, add a `CHECK_PARSE_BOOL` test.
> 
> https://github.com/cocos2d/cocos2d-objc has files without space and i would like add clang formatter for given project

That's not really a style guide, I can't find anyone there. And the last commit 8 years ago? Even the last issue is over 2 years old. Why not just add a `DisableFormat: true`?

https://github.com/llvm/llvm-project/pull/170579