* Replaces BuiltinProgram in the program-runtime with the one from solana_rbpf.
* Adjusts the runtimes built-ins to use Arc<LoadedProgram>.
* Adjusts the tests and benchmarks.
* Moves BuiltinProgram of the program runtime into its own file.
* Unifies the runtimes Builtin and program runtimes BuiltinProgram definitions.
* Moves BuiltinPrograms from bank.rs into the program runtime.