Fan Jiang

After a few fixes it now is able to generate object files without problem. However, the generated Mach-O files cannot run, because the Apple DYLD fails at the `fixup` step....

[test_macho.zip](https://github.com/zero9178/Pylir/files/9560608/test_macho.zip) generated mach-o for just one line `print("test!")`.

> Can you try if the `markAndSweep_tests` can be run? That executable also contains code generated py `pylir` but is linked via your system compiler (aka clang). That would narrow...

Finally found the culprit, quoting stack overflow: https://stackoverflow.com/questions/73382860/why-cant-i-assemble-absolute-addresses-in-the-text-section-on-arm64-macos/73382861#73382861 > Absolute addresses in the text section seem to be unsupported by ARM64 MacOS. As best I can tell, the dynamic linker...

Now that the thing is working, next step is to clean this mess up and possibly set up CI

Current lit-test result: [output.txt](https://github.com/zero9178/Pylir/files/9628243/output.txt)

There is a linking error with Catch2 and fmtlib that I haven't got time to debug: ``` Undefined symbols for architecture arm64: "fmt::v9::detail::assert_fail(char const*, int, char const*)", referenced from: std::__1::make_unsigned::type...

Maybe it's because your CMake did not specify the vendor version and it is finding my system lib?

``` echo $HISTFILE /var/folders/mw/96tsjxxxxxxxxxw0000gn/T/xxx-code-zsh/.zsh_history ``` Can confirm this bug on my M1 macOS Ventura

The bitvec library has not been maintained for more than half a year now, the issue was closed and there's no activity since. https://github.com/ferrilab/bitvec/pull/220 seems like a good alternative?