Compile 'index' with repr (not string) in EmbedNode

Before this fix, the generated Template code had quotes around the
index (integer) parameter value.

src/Node/EmbedNode.php

@@ -41,7 +41,7 @@ class EmbedNode extends IncludeNode
             ->raw(', ')
             ->repr($this->getTemplateLine())
             ->raw(', ')
-            ->string($this->getAttribute('index'))
+            ->repr($this->getAttribute('index'))
             ->raw(')')
         ;
         if ($this->getAttribute('ignore_missing')) {

tests/Node/EmbedTest.php

@@ -0,0 +1,91 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Twig\Tests\Node;
+
+use Twig\Node\EmbedNode;
+use Twig\Node\Expression\ArrayExpression;
+use Twig\Node\Expression\ConstantExpression;
+use Twig\Test\NodeTestCase;
+
+class EmbedTest extends NodeTestCase
+{
+    public function testConstructor()
+    {
+        $node = new EmbedNode('foo.twig', 0, null, false, false, 1);
+
+        $this->assertFalse($node->hasNode('variables'));
+        $this->assertEquals('foo.twig', $node->getAttribute('name'));
+        $this->assertEquals(0, $node->getAttribute('index'));
+        $this->assertFalse($node->getAttribute('only'));
+        $this->assertFalse($node->getAttribute('ignore_missing'));
+
+        $vars = new ArrayExpression([new ConstantExpression('foo', 1), new ConstantExpression(true, 1)], 1);
+        $node = new EmbedNode('bar.twig', 1, $vars, true, false, 1);
+        $this->assertEquals($vars, $node->getNode('variables'));
+        $this->assertTrue($node->getAttribute('only'));
+        $this->assertEquals('bar.twig', $node->getAttribute('name'));
+        $this->assertEquals(1, $node->getAttribute('index'));
+    }
+
+    public static function provideTests(): iterable
+    {
+        $tests = [];
+
+        $node = new EmbedNode('foo.twig', 0, null, false, false, 1);
+        $tests[] = [$node, <<<'EOF'
+// line 1
+yield from $this->load("foo.twig", 1, 0)->unwrap()->yield($context);
+EOF
+        ];
+
+        $node = new EmbedNode('foo.twig', 1, null, false, false, 1);
+        $tests[] = [$node, <<<'EOF'
+// line 1
+yield from $this->load("foo.twig", 1, 1)->unwrap()->yield($context);
+EOF
+        ];
+
+        $vars = new ArrayExpression([new ConstantExpression('foo', 1), new ConstantExpression(true, 1)], 1);
+        $node = new EmbedNode('foo.twig', 0, $vars, false, false, 1);
+        $tests[] = [$node, <<<'EOF'
+// line 1
+yield from $this->load("foo.twig", 1, 0)->unwrap()->yield(CoreExtension::merge($context, ["foo" => true]));
+EOF
+        ];
+
+        $node = new EmbedNode('foo.twig', 0, $vars, true, false, 1);
+        $tests[] = [$node, <<<'EOF'
+// line 1
+yield from $this->load("foo.twig", 1, 0)->unwrap()->yield(CoreExtension::toArray(["foo" => true]));
+EOF
+        ];
+
+        $node = new EmbedNode('foo.twig', 2, $vars, true, true, 1);
+        $tests[] = [$node, <<<EOF
+// line 1
+try {
+    \$_v0 = \$this->load("foo.twig", 1, 2);
+    \$_v0->getParent(\$context);
+;
+} catch (LoaderError \$e) {
+    // ignore missing template
+    \$_v0 = null;
+}
+if (\$_v0) {
+    yield from \$_v0->unwrap()->yield(CoreExtension::toArray(["foo" => true]));
+}
+EOF
+        ];
+
+        return $tests;
+    }
+}