Macro msg 

macro_rules! msg {
    ( $literal:expr ) => { ... };
    ( $fmt:expr, $($arg:tt)* ) => { ... };
}

Convenience macro for logging. Equivalent to hopper_native::log::log(msg).

Usage: msg!("Hello, {}", name);

On BPF, this formats into a stack buffer and calls sol_log_. For simple string literals, prefer hopper_native::log::log("...") directly.