[clang] [CFG] Add a BuildOption to consider default branch of switch on covered enumerations. (PR #161345)

[Fred Tingaud via cfe-commits]

frederic-tingaud-sonarsource wrote:

Pinging @gribozavr, @ymand and @sgatev as official maintainers of CFG analysis.

https://github.com/llvm/llvm-project/pull/161345