lib: add getLazy() method to internal/util

This patch adds a getLazy() method to facilitate initialize-once
lazy loading in the internals.

lib/internal/util.js

@@ -654,7 +654,25 @@ function isArrayBufferDetached(value) {
   return false;
 }
 
+/**
+ * @template T return value of loader
+ * @param {()=>T} loader
+ * @returns {()=>T}
+ */
+function getLazy(loader) {
+  let value;
+  let initialized = false;
+  return function() {
+    if (initialized === false) {
+      value = loader();
+      initialized = true;
+    }
+    return value;
+  };
+}
+
 module.exports = {
+  getLazy,
   assertCrypto,
   cachedResult,
   convertToValidSignal,