bare-arm/main: Add dummy memchr(), similar to other functions.
It's needed after adding it to str.format() code.
@@ -80,6 +80,7 @@ void *memcpy(void *dest, const void *src, size_t n) {return NULL;}
int memcmp(const void *s1, const void *s2, size_t n) {return 0;}
void *memmove(void *dest, const void *src, size_t n) {return NULL;}
void *memset(void *s, int c, size_t n) {return NULL;}
+void *memchr(const void *s, int c, size_t n) {return NULL;}
int strcmp(const char *s1, const char* s2) {return 0;}
int strncmp(const char *s1, const char* s2, size_t n) {return 0;}
size_t strlen(const char *s) {return 0;}
