bug#27866: Handle clang's internal libraries when finding compiler's internal libraries

Hi Ileana,

On Mon, 19 May 2025, Ileana Dumitrescu wrote:

> I decided to apply the proposed patches to development [1][2] for now.
> If there are any issues, I might revert these commits, but there will
> still be the option to use '--enable-cxx-stdlib' during configuration.

Thanks for taking care of this! What's the expected process for migrating 
patches further from development into master; will you revisit them in 
e.g. 6-12 months and consider including them in master if they haven't 
caused issues in the development branch since?

// Martin