Introduce the concept of builtin functions.

test/tools/yulopti.cpp

@@ -82,7 +82,7 @@ public:
 	{
 		ErrorReporter errorReporter(m_errors);
 		shared_ptr<Scanner> scanner = make_shared<Scanner>(CharStream(_input, ""));
-		m_ast = yul::Parser(errorReporter, yul::AsmFlavour::Strict).parse(scanner, false);
+		m_ast = yul::Parser(errorReporter, yul::Dialect::strictAssemblyForEVM()).parse(scanner, false);
 		if (!m_ast || !errorReporter.errors().empty())
 		{
 			cout << "Error parsing source." << endl;
@@ -95,7 +95,7 @@ public:
 			errorReporter,
 			EVMVersion::byzantium(),
 			boost::none,
-			AsmFlavour::Strict
+			Dialect::strictAssemblyForEVM()
 		);
 		if (!analyzer.analyze(*m_ast) || !errorReporter.errors().empty())
 		{