Add clarifying parenthesis around non-trivial conditions in ternary expressions. (#90391)

Fixes [#85868](https://github.com/llvm/llvm-project/issues/85868)

Parenthesis are added as requested on ternary operators with non trivial conditions.

I used this [precedence table](https://en.cppreference.com/w/cpp/language/operator_precedence) for reference, to make sure we get the expected behavior on each change.