Add methods for emitting diagnostics with no location as well as a special diagnostic for configuration errors.
These show up in the errors as [clang-tidy-config].
The reason to use a custom name rather than the check name is to distinguish the error isn't the same category as the check that reported it.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91885
Finds instances where variables with static storage are initialized dynamically in header files.
Reviewed By: aaron.ballman, alexfh
Patch by Charles Zhang!
Differential Revision: https://reviews.llvm.org/D62829
llvm-svn: 369568