Respect the line break

[lnshi]

I mean the case like:

or:

In either of these cases there are special intentions the developer groups the values or the function calls: for readability or group by semantics, current rustfmt just totally mess it up with simply calculating the line length....

Personally, I feel the direction that controlling the line length like setting all of these use_small_heuristics rules are pretty useless, maybe just do what gofmt is doing: respecting the line break, only deal with the blank line and indentions.

[calebcartwright]

Thanks for sharing your perspective, but I'm going to close this as a duplicate of #5085 (amongst various other issues) which raised the same topic within the last ~week.

(edit: corrected the linked issue number)