message: Fix compilation with mingw-w64 (pr37873)
diff: #include "lldb/lldb-types.h"
  -#if defined(_MSC_VER)
  +#if defined(_WIN32)
  #if defined(EXPORT_LIBLLDB)
  #define LLDB_API __declspec(dllexport)
  #elif defined(IMPORT_LIBLLDB)
  #else
  #define LLDB_API
  #endif
  -#else // defined (_MSC_VER)
  +#else // defined (_WIN32)
  #define LLDB_API
  #endif
  