Add Keccak256 syscall and sdk support (#16498)

sdk/bpf/c/inc/solana_sdk.h

@@ -437,6 +437,24 @@ uint64_t sol_sha256(
     const uint8_t *result
 );
 
+/**
+ * Length of a Keccak hash result
+ */
+#define KECCAK_RESULT_LENGTH 32
+
+/**
+ * Keccak
+ *
+ * @param bytes Array of byte arrays
+ * @param bytes_len Number of byte arrays
+ * @param result 32 byte array to hold the result
+ */
+uint64_t sol_keccak256(
+    const SolBytes *bytes,
+    int bytes_len,
+    const uint8_t *result
+);
+
 /**
  * Account Meta
  */