[wpiutil] Add wpi::scope_exit (#4432)

This is based on std::scope_exit in the C++ library fundamentals TS v3.

wpiutil/src/main/native/include/wpi/scope

@@ -0,0 +1,37 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#include <utility>
+
+namespace wpi {
+
+template <typename F>
+class scope_exit {
+ public:
+  explicit scope_exit(F&& f) noexcept : m_f{std::forward<F>(f)} {}
+
+  ~scope_exit() {
+    if (m_active) {
+      m_f();
+    }
+  }
+
+  scope_exit(scope_exit&& rhs) noexcept
+      : m_f{std::move(rhs.m_f)}, m_active{rhs.m_active} {
+    rhs.release();
+  }
+
+  scope_exit(const scope_exit&) = delete;
+  scope_exit& operator=(const scope_exit&) = delete;
+
+  void release() noexcept { m_active = false; }
+
+ private:
+  F m_f;
+  bool m_active = true;
+};
+
+}  // namespace wpi