[iwyu] Handle regressions in libLLVM header include

Running iwyu-diff on LLVM codebase since a96638e50e detected a few
regressions, fixing them.

llvm/include/llvm/Bitcode/BitcodeReader.h

@@ -15,7 +15,7 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Bitstream/BitCodes.h"
+#include "llvm/Bitstream/BitCodeEnums.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorOr.h"

llvm/lib/CodeGen/RegAllocGreedy.cpp

@@ -21,7 +21,6 @@
 #include "SplitKit.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/IndexedMap.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"

llvm/lib/CodeGen/TargetFrameLoweringImpl.cpp

@@ -15,7 +15,6 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/TargetFrameLowering.h"
-#include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/CallingConv.h"

llvm/lib/LTO/LTOBackend.cpp

@@ -18,7 +18,6 @@
 #include "llvm/Analysis/CGSCCPassManager.h"
 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/LLVMRemarkStreamer.h"
@@ -41,7 +40,6 @@
 #include "llvm/Support/ToolOutputFile.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/FunctionImportUtils.h"
 #include "llvm/Transforms/Utils/SplitModule.h"

llvm/lib/LTO/ThinLTOCodeGenerator.cpp

@@ -21,13 +21,13 @@
 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LLVMRemarkStreamer.h"
 #include "llvm/IR/Mangler.h"
@@ -53,7 +53,6 @@
 #include "llvm/Support/Threading.h"
 #include "llvm/Support/ToolOutputFile.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/FunctionAttrs.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
 #include "llvm/Transforms/IPO/Internalize.h"

llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp

@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "AArch64RegisterBankInfo.h"
-#include "AArch64InstrInfo.h"
 #include "AArch64RegisterInfo.h"
 #include "MCTargetDesc/AArch64MCTargetDesc.h"
 #include "llvm/ADT/STLExtras.h"

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -43,6 +43,7 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/NoFolder.h"
 #include "llvm/IR/Value.h"
+#include "llvm/IR/ValueHandle.h"     
 #include "llvm/Support/Alignment.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
@@ -51,8 +52,8 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/IPO/ArgumentPromotion.h"
-#include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
 #include <cassert>
 
 using namespace llvm;

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -53,7 +53,6 @@
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"