[clang] [clang][scan-build] Treat --use-cc and --use-c++ as shell commands (PR #131932)

[Balázs Benics via cfe-commits]

balazs-benics-sonarsource wrote:

Looks good as it is right now. Thanks for putting the effort into this.
I've invited the rest of the folks probably interested in this to get a second opinion.

https://github.com/llvm/llvm-project/pull/131932