[clang] [LifetimeSafety] Remove FactMgr parameter from buildOriginFlowChain (PR #201054)

[Yuan Suo via cfe-commits]

suoyuan666 wrote:

Ah, using PImpl is indeed simpler than my current implementation.

I will keep an eye on #201071, and once it has been merged, I will update `buildOriginFlowChain` in #199345 to follow this same pattern.

https://github.com/llvm/llvm-project/pull/201054