Use __cxa_guard stuff on Teensy 2.0

teensy/new.cpp

   free(ptr);
 }
 
-//int __cxa_guard_acquire(__guard *g) {return !*(char *)(g);};
-//void __cxa_guard_release (__guard *g) {*(char *)g = 1;};
-//void __cxa_guard_abort (__guard *) {}; 
+int __cxa_guard_acquire(__guard *g) {return !*(char *)(g);};
+void __cxa_guard_release (__guard *g) {*(char *)g = 1;};
+void __cxa_guard_abort (__guard *) {}; 
 
-//void __cxa_pure_virtual(void) {};
+void __cxa_pure_virtual(void) {};