Shader: Add EliminateUnusedPassVisitor and use it when optimizing

include/Nazara/Shader/Ast/EliminateUnusedPassVisitor.inl

@@ -0,0 +1,17 @@
+// Copyright (C) 2022 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Shader module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Shader/Ast/EliminateUnusedPassVisitor.hpp>
+#include <Nazara/Shader/Debug.hpp>
+
+namespace Nz::ShaderAst
+{
+	inline StatementPtr EliminateUnusedPass(Statement& ast)
+	{
+		EliminateUnusedPassVisitor visitor;
+		return visitor.Process(ast);
+	}
+}
+
+#include <Nazara/Shader/DebugOff.hpp>