[clang-tidy] cppcoreguidelines-macro-usage: print macro names


[clang-tidy] cppcoreguidelines-macro-usage: print macro names

The macro may not have location (or more generally, the location may not exist),
e.g. if it originates from compiler's command-line.

The check complains on all the macros, even those without the location info.
Which means, it only says it does not like it. What is 'it'? I have no idea.
If we don't print the name, then there is no way to deal with that situation.

And in general, not printing name here forces the user to try to understand,
given, the macro definition location, what is the macro name?
This isn't fun.

Also, ignores-by-default the macros originating from command-line,
with an option to not ignore those.

I suspect some more issues may crop up later.

Reviewers: JonasToth, aaron.ballman, hokein, xazax.hun, alexfh

Reviewed By: JonasToth, aaron.ballman

Subscribers: nemanjai, kbarton, rnkovacs, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D53817