Utilities: Implement pwd

Author: https://github.com/boricj
Commit: https://github.com/SerenityOS/serenity/commit/eb65e41a9cf
Pull-request: https://github.com/SerenityOS/serenity/pull/8567
Reviewed-by: https://github.com/MaxWipfli ✅
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/gunnarbeutner

Userland/Utilities/pwd.cpp

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main(int, char**)
+{
+    char* cwd = getcwd(nullptr, 0);
+    puts(cwd);
+    free(cwd);
+    return 0;
+}