parseLoopExpr

    pub fn parseLoopExpr(p: *Parser) Error!bool {
        const def_index = @backingInt(Def.defLoopExpr);
        if (p.depths[def_index] > max_depth) return error.MaxDepth;
        p.depths[def_index] += 1;
        defer p.depths[def_index] -= 1;
        return blk_0: {
            const pos_0 = p.i;
            if ((try p.parseKEYWORD_inline() or true) and blk_2: {
                const pos_2 = p.i;
                if (try p.parseForExpr()) break :blk_2 true;
                p.i = pos_2;
                if (try p.parseWhileExpr()) break :blk_2 true;
                p.i = pos_2;
                break :blk_2 false;
            }) break :blk_0 true;
            p.i = pos_0;
            break :blk_0 false;
        };
    }