[llvm] StructurizeCFG: Optimize phi insertion during ssa reconstruction (PR #101301)

[Yaxun Liu via llvm-commits]

yxsamliu wrote:

This PR seems to break HIP buildbot, causing Blender test to memfault: 

https://lab.llvm.org/buildbot/#/builders/123/builds/3282

local regression analysis showed the causing commit is from this PR.

Please revert it. Thanks.

https://github.com/llvm/llvm-project/pull/101301