Function make_format_spec

fn make_format_spec<'hir>(
    ctx: &mut LoweringContext<'_, 'hir>,
    sp: Span,
    placeholder: &FormatPlaceholder,
    argmap: &mut FxIndexMap<(usize, ArgumentType), Option<Span>>,
) -> Expr<'hir>

Generate a hir expression for a format_args placeholder specification.

Generates

    <core::fmt::rt::Placeholder {
        position: …usize,
        flags: …u32,
        precision: <core::fmt::rt::Count::…>,
        width: <core::fmt::rt::Count::…>,
    }