Update to 0.11.0-dev.1797+d3c9bfada and adds support for freestanding builds

[marler8997]

I've split this PR into 2 commits and merged them to main, one to update the build files (I also made all the build files work) and one to add the relpath trick in ziglibcbuild.zig.

• Update zig: https://github.com/marler8997/ziglibc/commit/2012a1d9b4646116b4a1a69c851edc6af16ae955
• Use relpath: https://github.com/marler8997/ziglibc/commit/db22b484c40eded37fab026c2e6d86d0c504192e

I didn't understand what the change was for to split some of the functions into a seperate freestanding library, what was that for?

[ikskuh]

I didn't understand what the change was for to split some of the functions into a seperate freestanding library, what was that for?

It's for making ziglibc work on freestanding targets (???-freestanding-???) which don't expose any I/O functionality, as no OS is present. freestanding is also a libc profile that should be supported in general (as it's specced by the C standard).

This is reqiured to use ziglibc on a non-standard target like a microcontroller, a custom OS and so on

[ikskuh]

Superseeded by #12