[llvm] utils/git: Add linkify script. (PR #103496)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

For this to work for me I have to do:
```
# Note: pager is an alias of less (here)
git config core.pager 'llvm/utils/git/linkify | pager -r'
```
`-r` forces less to interpret the ANSI codes.

Otherwise, it appears as:
```
 (8;;https://github.com/llvm/llvm-project/issues/101748#1017488;;)
```

---
Also, there may be some security implications from that... but I assume you can treat the LLVM repo as safe.

https://github.com/llvm/llvm-project/pull/103496