esp8266: Enable stack overflow checking.

esp8266/main.c

@@ -41,7 +41,8 @@
 STATIC char heap[16384];
 
 STATIC void mp_reset(void) {
-    mp_stack_set_limit(10240);
+    mp_stack_set_top((void*)0x40000000);
+    mp_stack_set_limit(8192);
     mp_hal_init();
     gc_init(heap, heap + sizeof(heap));
     mp_init();

esp8266/mpconfigport.h

@@ -10,7 +10,7 @@
 #define MICROPY_MEM_STATS           (0)
 #define MICROPY_DEBUG_PRINTERS      (1)
 #define MICROPY_ENABLE_GC           (1)
-#define MICROPY_STACK_CHECK         (0)
+#define MICROPY_STACK_CHECK         (1)
 #define MICROPY_REPL_EVENT_DRIVEN   (1)
 #define MICROPY_HELPER_REPL         (1)
 #define MICROPY_HELPER_LEXER_UNIX   (0)