Add extern "C" to declaration of scm_init_Swig_swigrun_module.

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@6028 626c5289-ae23-0410-ae9c-e8d60b6d4f22

SWIG/Lib/guile/guile_scm.swg

@@ -15,6 +15,9 @@
 /* Hook the runtime module initialization
    into the shared initialization function SWIG_Guile_Init. */
 #include <libguile.h>
+#ifdef __cplusplus
+extern "C"
+#endif
 SCM scm_init_Swig_swigrun_module (void);
 #define SWIG_INIT_RUNTIME_MODULE scm_init_Swig_swigrun_module();
 %}