func (st *state) sourceName() AST {
	val := st.number()
	if val <= 0 {
		st.fail("expected positive number")
	}
	if len(st.str) < val {
		st.fail("not enough characters for identifier")
	}
	id := st.str[:val]
	st.advance(val)

	// Look for GCC encoding of anonymous namespace, and make it
	// more friendly.
	const anonPrefix = "_GLOBAL_"
	if strings.HasPrefix(id, anonPrefix) && len(id) > len(anonPrefix)+2 {
		c1 := id[len(anonPrefix)]
		c2 := id[len(anonPrefix)+1]
		if (c1 == '.' || c1 == '_' || c1 == '$') && c2 == 'N' {
			id = "(anonymous namespace)"
		}
	}

	n := &Name{Name: id}
	return n
}
func (st *state) sourceName() AST {
	val := st.number()
	if val <= 0 {
		st.fail("expected positive number")
	}
	if len(st.str) < val {
		st.fail("not enough characters for identifier")
	}
	id := st.str[:val]
	st.advance(val)

	// Look for GCC encoding of anonymous namespace, and make it
	// more friendly.
	const anonPrefix = "_GLOBAL_"
	if strings.HasPrefix(id, anonPrefix) && len(id) > len(anonPrefix)+2 {
		c1 := id[len(anonPrefix)]
		c2 := id[len(anonPrefix)+1]
		if (c1 == '.' || c1 == '_' || c1 == '$') && c2 == 'N' {
			id = "(anonymous namespace)"
		}
	}

	n := &Name{Name: id}
	return n
}
// <source-name> ::= <(positive length) number> <identifier>
// identifier ::= <(unqualified source code identifier)>