Remove account executable flag

[Lichtso]

Problem

The executable flag was an architectural design mistake which both the accounts-db-team and the program-runtime-team want removed. During transaction loading we are already ignoring the executable flag of accounts and rely the owner being a loader instead:

solana/accounts-db/src/accounts.rs

Line 644 in b8115b4

pub fn filter_executable_program_accounts<'a>(

Proposed Solution

• Remove the remaining use sites of the executable flag during transaction loading:

  solana/accounts-db/src/accounts.rs

  Line 524 in b8115b4

  if !program_account.executable() {

• Move the PROGRAM_OWNERS list into the SDK:

  solana/runtime/src/bank.rs

  Line 5100 in b8115b4

  const PROGRAM_OWNERS: &[Pubkey] = &[

• Emulate the executable flag in BorrowedAccount::is_executable() the same way as in filter_executable_program_accounts():

  solana/sdk/src/transaction_context.rs

  Line 1001 in b8115b4

  pub fn is_executable(&self) -> bool {

• Remove BorrowedAccount::set_executable().