# Byte order mark and shebang

#!/usr/bin/env rustx
#![allow(dead_code)]
fn source_input() {}

==>

SourceFile(
  Shebang,
  InnerAttribute(MetaItem(Identifier, ParenthesizedTokens(Identifier))),
  FunctionItem(fn, BoundIdentifier, ParamList, Block))


# Inner attribute after whitespace

#! [allow(dead_code)]
fn retained() {}

==>

SourceFile(
  InnerAttribute(MetaItem(Identifier, ParenthesizedTokens(Identifier))),
  FunctionItem(fn, BoundIdentifier, ParamList, Block))