Tracking issue for experimental "time" feature

This issue tracks the experimental "time" feature.

Enable semihosting::experimental::time.

Open issues

now currently always fails on MIPS. AFAIK, UHI doesn't provide any time-related features.

Lines 21 to 24 in 1b82359

    
           pub fn now() -> Self { 
        
               // TODO: this always fails on MIPS/MIPS64 
        
               Self(time::SystemTime::now().unwrap()) 
        
           }

ARM and RISC-V's SystemTime implementation will likely be affected by the Y2038 on 32-bit systems.
Currently, only SystemTime is implemented. ARM/RISC-V semihosting seems to provide the functionality needed to implement Instant, but it will likely be more complex than SystemTime.

TODO: write more on open issues

	pub fn now() -> Self {
	// TODO: this always fails on MIPS/MIPS64
	Self(time::SystemTime::now().unwrap())
	}