Fix an MSVC debug break
With the latest master I started getting:
"A breakpoint instruction (__debugbreak() statement or a similar call) was executed in Stockfish.exe." when debugging in MSVC.
I don't really understand the issue but Fable fixed it and I verified it works.
Here is its summary:
Bug: Calling _get_wpgmptr() in CommandLine::get_binary_directory() triggered a debug CRT assertion failure (__debugbreak()) on Windows. The CRT only initializes the wide program name _wpgmptr when the application uses a wide entry point (wmain). Since Stockfish uses the narrow main(int, char**) entry point, _wpgmptr remains nullptr, and the debug CRT's parameter validation asserts when _get_wpgmptr is called.
Fix: Replaced _get_wpgmptr() with GetModuleFileNameW(), which queries the executable path directly from the OS and does not depend on the CRT entry point type. The implementation uses a grow-and-retry loop, so paths longer than MAX_PATH are handled correctly. If the API fails, the code falls back to the original argv0-based behavior. The #ifdef _MSC_VER guard was also removed, since the fix no longer relies on the MSVC CRT — non-MSVC Windows builds (e.g., MinGW) now benefit from the accurate path as well.
closes https://github.com/official-stockfish/Stockfish/pull/6972
No functional change