Added a first fuzzer.

test/fuzzers/fuzz_dostring.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <string.h>
+#include <janet.h>
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size){
+	char *new_str = (char *)malloc(size+1);
+	if (new_str == NULL){
+		return 0;
+	}
+	memcpy(new_str, data, size);
+	new_str[size] = '\0';
+
+	/* janet logic */
+	janet_init();
+	JanetTable *env = janet_core_env(NULL);
+	janet_dostring(env, new_str, "main", NULL);
+	janet_deinit();
+
+	free(new_str);
+	return 0;
+}
+