[llvm] [BranchRelaxation] Remove quadratic behavior in relaxation pass (PR #96250)

[Mingming Liu via llvm-commits]

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@@ -718,6 +734,13 @@ bool BranchRelaxation::relaxBranchInstructions() {
     }
   }
 
+  // If we relaxed a branch, subsequent block offsets may be underestimated.
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minglotus-6 wrote:

nit: Call out explicitly that `adjustBlockOffsets run over all MBBs if any BB is relaxed` 

https://github.com/llvm/llvm-project/pull/96250