Add Composer autoloading functions and PHPStan for testing

vendor/nikic/php-parser/lib/PhpParser/Builder/Function_.php

@@ -0,0 +1,50 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Builder;
+
+use PhpParser;
+use PhpParser\BuilderHelpers;
+use PhpParser\Node;
+use PhpParser\Node\Stmt;
+
+class Function_ extends FunctionLike
+{
+    protected $name;
+    protected $stmts = [];
+
+    /**
+     * Creates a function builder.
+     *
+     * @param string $name Name of the function
+     */
+    public function __construct(string $name) {
+        $this->name = $name;
+    }
+
+    /**
+     * Adds a statement.
+     *
+     * @param Node|PhpParser\Builder $stmt The statement to add
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function addStmt($stmt) {
+        $this->stmts[] = BuilderHelpers::normalizeStmt($stmt);
+
+        return $this;
+    }
+
+    /**
+     * Returns the built function node.
+     *
+     * @return Stmt\Function_ The built function node
+     */
+    public function getNode() : Node {
+        return new Stmt\Function_($this->name, [
+            'byRef'      => $this->returnByRef,
+            'params'     => $this->params,
+            'returnType' => $this->returnType,
+            'stmts'      => $this->stmts,
+        ], $this->attributes);
+    }
+}