Add msg! macro for program logging, deprecate info! macro

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

@@ -3,7 +3,7 @@
 extern crate solana_program;
 use solana_program::{
     hash::{hashv, Hasher},
-    info,
+    msg,
 };
 
 fn test_hasher() {
@@ -15,7 +15,7 @@ fn test_hasher() {
 
 #[no_mangle]
 pub extern "C" fn entrypoint(_input: *mut u8) -> u64 {
-    info!("sha256");
+    msg!("sha256");
 
     test_hasher();