Implement C23 const-preserving standard library macros

[Frank Scheiner]

On 26.11.25 12:36, Frank Scheiner wrote:
> So will you come up with a patch for binutils regarding CALL_UTIL?
> 
> If you like to fix the warnings, too, please do. But I can also try
> to come up with a patch for binutils regarding these warnings myself.
> Unless this was already done but not pushed yet, need to check.

UPDATE: I had the time, so I fixed the warnings right-away. Currently
testing the binutils patch with our toolchain autobuilder on [1].

[1]: https://github.com/johnny-mnemonic/toolchain-autobuilds/actions/runs/19708658599

Cheers,
Frank