* 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
The core/src/ directory is already pretty crowded, and moving these
items into the subdirectory more clearly identifies that they are tied
to banking_stage.
Lucas Steuernagel
Pankaj Garg
steviez
Andrew Fitzgerald