clang-tidy fails to parse config files silently, even with --verify-config.

[knjmooney]

If you have an invalid clang-tidy config file, clang-tidy carries on silently and uses the default configuration settings. I've encountered this in several projects where there is a typo in the clang-tidy config file, which results in the default config being used.

With verify-config, the errors are reported, but it eventually claims "No config error detected" and sets a successful exit code.

 -> clang-tidy-17 --version                                    
Ubuntu LLVM version 17.0.4
  Optimized build.

 -> echo "This is not a valid clang-tidy file" > .clang-tidy   
                                                                                                                                                                                                                                                                                                                              
 -> clang-tidy-17 --verify-config && echo PASSED || echo FAILED
/tmp/test/.clang-tidy:1:1: error: not a mapping
This is not a valid clang-tidy file
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Error parsing /tmp/test/.clang-tidy: Invalid argument
/tmp/test/.clang-tidy:1:1: error: not a mapping
This is not a valid clang-tidy file
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Error parsing /tmp/test/.clang-tidy: Invalid argument
No config errors detected.
PASSED