[lld] [llvm] [LLVM][LTO] Factor out RTLib calls and allow them to be dropped (PR #98512)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

Note: this is not incremental bot, every time it removes build dir, so this is not incremental CMake issue.

I believe 
```
DEPENDS
  vt_gen
  intrinsics_gen
```

I'll try and patch


https://github.com/llvm/llvm-project/pull/98512