pulse2rust omits parentheses

[gebner]

I only noticed this today, but the prettyplease library doesn't insert parentheses if the operator precedence requires it (nor does anything else in the syn ecosystem as far as I can tell).

module Binop

let f (x y z: (a:UInt64.t { UInt64.v a < 100 })) =
  UInt64.mul x (UInt64.add y z)

fstar.exe --codegen Extension --extract_module Binop Binop.fst
pulse2rust/main.exe -odir . Binop.ast

////
////
//// This file is generated by the Pulse2Rust tool
////
////

pub fn f(x: u64, y: u64, z: u64) -> u64 {
    x * y + z
}