getNextTypeIndex = ast => {
	const typeSectionMetadata = t.getSectionMetadata(ast, "type");

	if (typeSectionMetadata === undefined) {
		return t.indexLiteral(0);
	}

	return t.indexLiteral(typeSectionMetadata.vectorOfSize.value);
}
Get next type index
@param {AST} ast Module's AST
@returns {t.Index} - index