[lld] [lld][ELF] Support LLVM repository and LLVM revision information (PR #97323)

[Petr Hosek via llvm-commits]

petrhosek wrote:

> The description (which will be used as the default commit message when "Squash and merge" is clicked) is probably about `LLVM_APPEND_VC_REV=on`.
> 
> > I'd also consider removing the parenthesis around the compatible with GNU linkers part in the ELF driver so we end up with:
> 
> In the `LLVM_APPEND_VC_REV=off` configuration,
> 
> ```
> % fld.lld --version
> LLD 19.0.0 compatible with GNU linkers
> ```
> 
> Without parentheses, "compatible ..." might be parsed as part of the version string.
> 
> Should parentheses be added back? We could also use a leading comma or something else, but lld/MinGW/Driver.cpp should be updated as well for consistency.

Looks like [mold uses the following format](https://github.com/rui314/mold/blob/b145377c39de8ed9b6ee3b1106cdf206fafe1605/elf/config.cc): 

```
$ ld.lld --version
LLD 19.0.0 (https://github.com/yugier/llvm-project.git 4134b33c6a362cb462b335177d6d9e8235f04309; compatible with GNU ld)
```

Should we use the same format for consistency?

https://github.com/llvm/llvm-project/pull/97323