Revert rG5dd566b7c7b78bd- "PassManager.h - remove unnecessary Function.h/Module.h includes. NFCI."

This reverts commit 5dd566b7c7b78bd385418c72d63c79895be9ae97.

Causing some buildbot failures that I'm not seeing on MSVC builds.
diff --git a/llvm/lib/CodeGen/MachineSizeOpts.cpp b/llvm/lib/CodeGen/MachineSizeOpts.cpp
index e19862e..584d43b 100644
--- a/llvm/lib/CodeGen/MachineSizeOpts.cpp
+++ b/llvm/lib/CodeGen/MachineSizeOpts.cpp
@@ -12,10 +12,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/MachineSizeOpts.h"
-#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/CodeGen/MBFIWrapper.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
-#include "llvm/IR/Function.h"
 
 using namespace llvm;