[C++] Switch to std::any and deprecate antlrcpp::Any

[jcking]

Remove antlrcpp::Any in favor of std::any. Unfortunately there is no good story for backwards compatibility as std::any is a smaller feature set and only supports static_cast.

[jcking]

@mike-lischke I kept antlrcpp::Any as a type alias to std::any to at least make the error people will get more clear and require less changes overall. We can remove antlrcpp::Any at some point in the future.

[mike-lischke]

The patch looks good, however in the build output I see 3 warnings, that should be fixed. No idea when this creeped in, but I see now:

/tmp/BaseCppTest-main-1638301471082/TParser.cpp:79:29: warning: explicit capture of 'this' with a capture default of '=' is a C++20 extension [-Wc++20-extensions]
auto onExit = finally([=, this] {

Then we get a number of warnings because of the recently deprecated EMPTY_VOCABULARY.

And finally a (probably old) problem with an implicit switch fall through. See the C++ build output in CircleCI.

Can you fix those too?

[KvanTTT]

/tmp/BaseCppTest-main-1638301471082/TParser.cpp:79:29: warning: explicit capture of 'this' with a capture default of '=' is a C++20 extension [-Wc++20-extensions]

It looks like has been fixed recently: #3393

[jcking]

Fixed everything except EMPTY_VOCABULARY. I'll fix that in a standalone CL. The C++20 warning was fixed in a separate CL after I noticed it. I had misread a preprocessor condition as checking for C++ 17 when it was checking for C++ 20.

[mike-lischke]

@parrt Another C++ patch to merge. There are some build errors, but from what I see they are all caused by configuration problems on CircleCI.

[parrt]

Ok, yeah, I think I broke everything yesterday outside of Circleci