JSSpecCompiler: Add --dump-cfg option

Author: https://github.com/DanShaders
Commit: ce6b987330
Pull-request: https://github.com/SerenityOS/serenity/pull/22222

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Compiler/ControlFlowGraph.cpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2023, Dan Klishch <danilklishch@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/StringBuilder.h>
+
+#include "AST/AST.h"
+#include "Compiler/ControlFlowGraph.h"
+
+using namespace JSSpecCompiler;
+
+ErrorOr<void> AK::Formatter<ControlFlowGraph>::format(FormatBuilder& format_builder, ControlFlowGraph const& control_flow_graph)
+{
+    auto& builder = format_builder.builder();
+
+    for (auto const& block : control_flow_graph.blocks) {
+        builder.appendff("{}:\n", block->m_index);
+        for (auto const& expression : block->m_expressions)
+            builder.appendff("{}", expression);
+        builder.appendff("{}\n", Tree(block->m_continuation));
+    }
+
+    // Remove trailing \n
+    builder.trim(1);
+
+    return {};
+}