[clang] [clang-format] allow short function body on a single line (PR #151428)

[Lidong Yan via cfe-commits]

brandb97 wrote:

I can just fix the bug by moving `PutShortFunctionBodiesOnASingleLine` to private area in FormatStyle and set `PutShortFunctionBodiesOnASingleLine` to `Always` if and only if `AllowShortFunctionsOnASingleLine` is `Never` and `AllowShortBlocksOnASingleLine` is `Always`. Is that what I should do?

https://github.com/llvm/llvm-project/pull/151428