fn expr_to_lit(
psess: &ParseSess,
expr: &Expr,
span: Span,
should_emit: ShouldEmit,
) -> Option<MetaItemLit>
fn expr_to_lit(
psess: &ParseSess,
expr: &Expr,
span: Span,
should_emit: ShouldEmit,
) -> Option<MetaItemLit>