extmod/re1.5: Upgrade to v0.8.2, adds hook for stack overflow checking.

extmod/re1.5/re1.5.h

@@ -48,6 +48,9 @@ void printre(Regexp*);
 #ifndef re1_5_fatal
 void re1_5_fatal(char*);
 #endif
+#ifndef re1_5_stack_chk
+#define re1_5_stack_chk()
+#endif
 void *mal(int);
 
 struct Prog

extmod/re1.5/recursiveloop.c

@@ -10,6 +10,8 @@ recursiveloop(char *pc, const char *sp, Subject *input, const char **subp, int n
 	const char *old;
 	int off;
 
+	re1_5_stack_chk();
+
 	for(;;) {
 		if(inst_is_consumer(*pc)) {
 			// If we need to match a character, but there's none left, it's fail