Maybe these `_suffixed` function could be merged into their non-`_sufifxed` counterparts?

```rust
enum SuffixMode { ForceSuffix, AutoSuffix }

pub fn int_ty_to_str(t: IntTy, val: Option<i64>, suffix: SuffixMode) -> StrBuf { ... }
```

rather than introducing two new functions for a single call each. (One might consider adding a wrapper that passes `AutoSuffix`, if there are a lot of calls with that mode.)