test_runner: fixing PR comments

* Adds lcov reporter to docs examples
* Corrects comment with period after URL
* Use ReflectConstruct so that the lcov reporter class is usable as a
function

doc/api/test.md

@@ -662,11 +662,11 @@ to the test runner's output is required, use the events emitted by the
 The reporters are available via the `node:test/reporters` module:
 
 ```mjs
-import { tap, spec, dot, junit } from 'node:test/reporters';
+import { tap, spec, dot, junit, lcov } from 'node:test/reporters';
 ```
 
 ```cjs
-const { tap, spec, dot, junit } = require('node:test/reporters');
+const { tap, spec, dot, junit, lcov } = require('node:test/reporters');
 ```
 
 ### Custom reporters

lib/internal/test_runner/reporter/lcov.js

@@ -3,9 +3,9 @@
 const Transform = require('internal/streams/transform');
 
 // This reporter is based on the LCOV format, as described here:
-// https://ltp.sourceforge.net/coverage/lcov/geninfo.1.php. Excerpts from this
-// documentation are included in the comments that make up the _transform
-// function below.
+// https://ltp.sourceforge.net/coverage/lcov/geninfo.1.php
+// Excerpts from this documentation are included in the comments that make up
+// the _transform function below.
 class LcovReporter extends Transform {
   constructor(options) {
     super({ ...options, writableObjectMode: true, __proto__: null });

lib/test/reporters.js

@@ -52,7 +52,7 @@ ObjectDefineProperties(module.exports, {
     enumerable: true,
     get() {
       lcov ??= require('internal/test_runner/reporter/lcov');
-      return lcov;
+      return ReflectConstruct(lcov, arguments);
     },
   },
 });