std: Drop Total from Total{Eq,Ord}

This completes the last stage of the renaming of the comparison hierarchy of
traits. This change renames TotalEq to Eq and TotalOrd to Ord.

In the future the new Eq/Ord will be filled out with their appropriate methods,
but for now this change is purely a renaming change.

[breaking-change]
auto merge of #14579 : alexcrichton/rust/more-eq-renamings, r=thestinger

This completes the last stage of the renaming of the comparison hierarchy of
traits. This change renames TotalEq to Eq and TotalOrd to Ord.

In the future the new Eq/Ord will be filled out with their appropriate methods,
but for now this change is purely a renaming change.

This continues the work of #12517, continuing the work in #14534. This patch accomplishes the final rename of `TotalEq` to `TotalOrd`. I wanted to get this patch landed ASAP so we don't have to deal much with "where did `Eq` and `Ord` go?"

I have yet to do another pruning pass over the compiler to change all usage of `PartialEq` to `Eq` where appropriate. I will do this soon as well.