[llvm] [LoopFusion] Cleanup control flow before Fusion (PR #226289)

[Congzhe Cao via llvm-commits]

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@@ -0,0 +1,389 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -S -passes=loop-fusion < %s | FileCheck %s
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CongzheUalberta wrote:

In the test cases added, can we verify LI and DT to make sure they are updated correctly, something like `-verify-loop-info -verify-dom-info`? For loop fusion in the past there were a number of bugs exposed by not updating the LI or DT correctly. 

https://github.com/llvm/llvm-project/pull/226289