add sha256 syscall (#12569)

programs/bpf/rust/sha256/src/lib.rs

@@ -0,0 +1,19 @@
+//! @brief SHA256 Syscall test
+
+extern crate solana_sdk;
+use solana_sdk::{
+    hash::{hashv, Hasher},
+    info,
+};
+
+#[no_mangle]
+pub extern "C" fn entrypoint(_input: *mut u8) -> u64 {
+    info!("sha256");
+
+    let vals = &["Gaggablaghblagh!".as_ref(), "flurbos".as_ref()];
+    let mut hasher = Hasher::default();
+    hasher.hashv(vals);
+    assert_eq!(hashv(vals), hasher.result());
+
+    0
+}