[llvm] [ORC] Add automatic shared library resolver for unresolved symbols. (PR #148410)

[Vassil Vassilev via llvm-commits]

vgvassilev wrote:

> One more task I need to complete is moving the code from **Orc/TargetProcess** to **Orc/Shared**, so that it can be used on the Root side as an API.

Probably that’s a question for @lhames. I am fine with that change considering the fact that we will rework that part when the new orc runtime shapes up. 

> 
> Also, before merging, can we make sure the unit tests are running correctly? Right now, they only work for Mach-O binaries. I created a fat binary (**x86_64 + arm64 + arm64e**) YAML, where the x86_64 and arm64e parts were cross-compiled, and I generated the YAML file. However, I’ve only tested it on **arm64**, not on **x86_64**.

I can take this PR and run the test suite on Unix 64bit platform. Is that enough?

https://github.com/llvm/llvm-project/pull/148410