* Initialize fork graph in program cache during bank_forks creation
* rename BankForks::new to BankForks::new_rw_arc
* fix compilation
* no need to set fork_graph on insert()
* fix partition tests
* remove unnecessary hashes around raw string literals
* remove unncessary literal `unwrap()`s
* remove panicking `unwrap()`
* remove unnecessary `unwrap()`
* use `[]` instead of `vec![]` where applicable
* remove (more) unnecessary explicit `into_iter()` calls
* remove redundant pattern matching
* don't cast to same type and constness
* do not `cfg(any(...` a single item
* remove needless pass by `&mut`
* prefer `or_default()` to `or_insert_with(T::default())`
* `filter_map()` better written as `filter()`
* incorrect `PartialOrd` impl on `Ord` type
* replace "slow zero-filled `Vec` initializations"
* remove redundant local bindings
* add required lifetime to associated constant
Pankaj Garg
Trent Nelson
Brooks
Jeff Biseda