SpillPlacement.cpp - remove unnecessary includes. NFCI.

These are all directly included in SpillPlacement.h

llvm/lib/CodeGen/SpillPlacement.cpp

@@ -27,10 +27,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "SpillPlacement.h"
-#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/SparseSet.h"
 #include "llvm/CodeGen/EdgeBundles.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
@@ -39,7 +36,6 @@
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
-#include "llvm/Support/BlockFrequency.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>