Refactor - Moves the system program into its own crate

Cargo.toml

@@ -61,6 +61,7 @@ members = [
     "programs/ed25519-tests",
     "programs/loader-v3",
     "programs/stake",
+    "programs/system",
     "programs/vote",
     "programs/zk-token-proof",
     "programs/zk-token-proof-tests",
@@ -348,6 +349,7 @@ solana-storage-bigtable = { path = "storage-bigtable", version = "=1.16.0" }
 solana-storage-proto = { path = "storage-proto", version = "=1.16.0" }
 solana-streamer = { path = "streamer", version = "=1.16.0" }
 solana-sys-tuner = { path = "sys-tuner", version = "=1.16.0" }
+solana-system-program = { path = "programs/system", version = "=1.16.0" }
 solana-test-validator = { path = "test-validator", version = "=1.16.0" }
 solana-thin-client = { path = "thin-client", version = "=1.16.0" }
 solana-tpu-client = { path = "tpu-client", version = "=1.16.0", default-features = false }

programs/system/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "solana-system-program"
+description = "Solana System program"
+documentation = "https://docs.rs/solana-system-program"
+version = { workspace = true }
+authors = { workspace = true }
+repository = { workspace = true }
+homepage = { workspace = true }
+license = { workspace = true }
+edition = { workspace = true }
+
+[dependencies]
+bincode = { workspace = true }
+log = { workspace = true }
+serde = { workspace = true }
+serde_derive = { workspace = true }
+solana-program-runtime = { workspace = true }
+solana-sdk = { workspace = true }
+
+[dev-dependencies]
+assert_matches = { workspace = true }
+solana-logger = { workspace = true }
+
+[lib]
+crate-type = ["lib"]
+name = "solana_system_program"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

programs/system/src/lib.rs

@@ -0,0 +1,34 @@
+#![allow(clippy::integer_arithmetic)]
+pub mod system_instruction;
+pub mod system_processor;
+
+use solana_sdk::{
+    account::{AccountSharedData, ReadableAccount},
+    account_utils::StateMut,
+    nonce, system_program,
+};
+pub use system_program::id;
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum SystemAccountKind {
+    System,
+    Nonce,
+}
+
+pub fn get_system_account_kind(account: &AccountSharedData) -> Option<SystemAccountKind> {
+    if system_program::check_id(account.owner()) {
+        if account.data().is_empty() {
+            Some(SystemAccountKind::System)
+        } else if account.data().len() == nonce::State::size() {
+            let nonce_versions: nonce::state::Versions = account.state().ok()?;
+            match nonce_versions.state() {
+                nonce::State::Uninitialized => None,
+                nonce::State::Initialized(_) => Some(SystemAccountKind::Nonce),
+            }
+        } else {
+            None
+        }
+    } else {
+        None
+    }
+}