[llvm] [Codegen] (NFC) Faster algorithm for MachineBlockPlacement (PR #91843)

[David Li via llvm-commits]

================
@@ -3118,7 +3158,16 @@ bool MachineBlockPlacement::maybeTailDuplicateBlock(
 
         // Handle the filter set
         if (BlockFilter) {
-          BlockFilter->remove(RemBB);
+          auto It = llvm::find(*BlockFilter, RemBB);
----------------
david-xl wrote:

Add a comment for the code below.

https://github.com/llvm/llvm-project/pull/91843