v0.4.0 - feature cortex-m not available

You have removed the features (e.g. cortex-m) in the new version, but you are checking for with cfg in code for it:

Lines 26 to 30 in 4d8bdd8

    
           #[cfg(any(feature = "cortex-m", feature = "riscv"))] 
        
           #[macro_export] 
        
           macro_rules! debug_rtt_init_print { 
        
               ($($arg:tt)*) => (if cfg!(debug_assertions) { $crate::rtt_init_print!($($arg)*); }) 
        
           }

This issue renders "rtt-target" v0.4.0 (the latest at the moment) unusable, at least on Cortex-M targets 😞

Also notice that v0.4.0 declares no feature-flags at all: https://docs.rs/crate/rtt-target/0.4.0/features

I am having this issue as well. Attempting to build a binary against it results in linker errors for undefined symbols _critical_section_1_0_acquire and _critical_section_1_0_release.

	#[cfg(any(feature = "cortex-m", feature = "riscv"))]
	#[macro_export]
	macro_rules! debug_rtt_init_print {
	($($arg:tt)) => (if cfg!(debug_assertions) { $crate::rtt_init_print!($($arg)); })
	}