C++26: the new debugging header sandordargo.com

C++26 adds a `<debugging>` header with `std::breakpoint()`, `std::is_debugger_present()` and `std::breakpoint_if_debugging()` for setting breakpoints and checking whether a debugger is attached. Sandor Dargo explains the functions standardized by proposals P2546R5 and P2810R4, credited to Rene Ferdinand Rivera Morell, and notes that debugger detection can be replaced by platform-specific implementations.