Remove redundant _SQ64 define

This is already defined in the Squirrel itself:

* external/squirrel/CMakeLists.txt:49

Author: Grumbel

config.h.cmake

@@ -8,13 +8,6 @@
 #define INSTALL_SUBDIR_BIN "${INSTALL_SUBDIR_BIN}"
 #define INSTALL_SUBDIR_SHARE "${INSTALL_SUBDIR_SHARE}"
 
-#ifndef EMSCRIPTEN
-#define SIZEOF_VOID_P ${CMAKE_SIZEOF_VOID_P}
-#if SIZEOF_VOID_P == 8
-#define _SQ64
-#endif
-#endif
-
 #cmakedefine HAVE_ICONV_CONST
 #ifdef HAVE_ICONV_CONST
 #define ICONV_CONST const