[llvm] X86: Add prefetch insertion based on Propeller profile (PR #166324)

[Simon Pilgrim via llvm-commits]

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@@ -42,6 +42,17 @@ struct BBClusterInfo {
   unsigned PositionInCluster;
 };
 
+struct BBPosition {
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RKSimon wrote:

(style) public data structures need dxoygen descriptions

https://github.com/llvm/llvm-project/pull/166324