* Return error if Transaction locks an executable as writable
* Return error if a ProgramData account is writable but the upgradable loader isn't present
* Remove unreachable clause
* Fixup bpf tests
* Review comments
* Add new TransactionError
* Disallow writes to any upgradeable-loader account when loader not present; remove is_upgradeable_loader_present exception for all other executables
* added realtime cost checking logic to reject block that would exceed max limit:
- defines max limits at block_cost_limits.rs
- right after each bath's execution, accumulate its cost and check again
limit, return error if limit is exceeded
* update abi that changed due to adding additional TransactionError
* To avoid counting stats mltiple times, only accumulate execute-timing when a bank is completed
* gate it by a feature
* move cost const def into block_cost_limits.rs
* redefine the cost for signature and account access, removed signer part as it is not well defined for now
* check if per_program_timings of execute_timings before sending
Tyera Eulberg
Justin Starry
Tao Zhu
Trent Nelson