implement mktemp

tests/stdlib/mktemp.c

@@ -0,0 +1,12 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char** argv) {
+    char* string = (char*) calloc(20, sizeof(char));
+    strcpy(string, "tempXXXXXX");
+    mktemp(string);
+    printf("%s\n",string);
+    free(string);
+    return 0;
+}