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

[Nathan Corbyn via llvm-commits]

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

I tried forward declaring `BatchAAResults` in `MachinePipeliner.h`, but it uses the type in the definition of `SwingSchedulerDAG`.

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