Add msg! macro for program logging, deprecate info! macro (#13885)

(cherry picked from commit 6705b5a98c)

Co-authored-by: Michael Vines <mvines@gmail.com>

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

@@ -4,7 +4,7 @@ use solana_program::{
     account_info::AccountInfo,
     entrypoint,
     entrypoint::{ProgramResult, HEAP_LENGTH, HEAP_START_ADDRESS},
-    info,
+    msg,
     pubkey::Pubkey,
 };
 use std::{
@@ -58,7 +58,7 @@ fn process_instruction(
     _accounts: &[AccountInfo],
     _instruction_data: &[u8],
 ) -> ProgramResult {
-    info!("Custom heap");
+    msg!("Custom heap");
     unsafe {
         let layout = Layout::from_size_align(usize::MAX - 0x42, align_of::<u8>()).unwrap();
         let ptr = alloc(layout);