Merge InstructionError and ProgramError

From the user's perspective, it's just an instruction error.
For program-specific errors, we still have
InstructionError::CustomError.

sdk/src/native_program.rs

@@ -1,50 +1,6 @@
 use crate::account::KeyedAccount;
 use crate::pubkey::Pubkey;
-use std;
-
-/// Reasons a program might have rejected an instruction.
-#[derive(Debug, PartialEq, Eq, Clone)]
-pub enum ProgramError {
-    /// The program instruction returned an error
-    GenericError,
-
-    /// The arguments provided to a program instruction where invalid
-    InvalidArgument,
-
-    /// An instruction's data contents was invalid
-    InvalidInstructionData,
-
-    /// An account's data contents was invalid
-    InvalidAccountData,
-
-    /// An account's data was too small
-    AccountDataTooSmall,
-
-    /// The account did not have the expected program id
-    IncorrectProgramId,
-
-    /// A signature was required but not found
-    MissingRequiredSignature,
-
-    /// An initialize instruction was sent to an account that has already been initialized.
-    AccountAlreadyInitialized,
-
-    /// An attempt to operate on an account that hasn't been initialized.
-    UninitializedAccount,
-
-    /// CustomError allows on-chain programs to implement program-specific error types and see
-    /// them returned by the Solana runtime. A CustomError may be any type that is serialized
-    /// to a Vec of bytes, max length 32 bytes. Any CustomError Vec greater than this length will
-    /// be truncated by the runtime.
-    CustomError(Vec<u8>),
-}
-
-impl std::fmt::Display for ProgramError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "error")
-    }
-}
-impl std::error::Error for ProgramError {}
+use crate::transaction::InstructionError;
 
 // All native programs export a symbol named process()
 pub const ENTRYPOINT: &str = "process";
@@ -55,7 +11,7 @@ pub type Entrypoint = unsafe extern "C" fn(
     keyed_accounts: &mut [KeyedAccount],
     data: &[u8],
     tick_height: u64,
-) -> Result<(), ProgramError>;
+) -> Result<(), InstructionError>;
 
 // Convenience macro to define the native program entrypoint.  Supply a fn to this macro that
 // conforms to the `Entrypoint` type signature.
@@ -68,7 +24,7 @@ macro_rules! solana_entrypoint(
             keyed_accounts: &mut [KeyedAccount],
             data: &[u8],
             tick_height: u64
-        ) -> Result<(), ProgramError> {
+        ) -> Result<(), InstructionError> {
             $entrypoint(program_id, keyed_accounts, data, tick_height)
         }
     )