[llvm] [MISched](NFC) Factor control dependency construction state and logic out of `buildSchedGraph` (PR #226533)

[Nathan Corbyn via llvm-commits]

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@@ -42,6 +42,7 @@
 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
+#include "llvm/Analysis/AliasAnalysis.h"
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cofibrant wrote:

Could we add `AliasAnalysis.h` to the LLVM-CodeGen PCH directly?

https://github.com/llvm/llvm-project/pull/226533