[llvm] [LSR] Optimize lsr-term-fold if the operand of condition is PHINode (PR #96048)

[Zhijin Zeng via llvm-commits]

zengdage wrote:

@eopXD Hi, can you help to review the patch? I extend the terminator folding to multiple exits loop and  support that the operand of the branch condition within the latch terminator  is `PHINode`.  Thank you.

https://github.com/llvm/llvm-project/pull/96048