[llvm] [CodeGen] Port `IndirectBrExpand` to new pass manager (PR #75287)

[Matt Arsenault via llvm-commits]

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@@ -1,4 +1,5 @@
-//===- IndirectBrExpandPass.cpp - Expand indirectbr to switch -------------===//
+//===- IndirectBrExpandLegacyPass.cpp - Expand indirectbr to switch
+//-------------===//
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arsenm wrote:

Fix comment line break 

https://github.com/llvm/llvm-project/pull/75287