[TTI] Sink IVDescriptors.h include (NFC)

Forward declare RecurrenceDescriptor and include IVDescritor.h
only in implementation code that actually needs it.

llvm/include/llvm/Analysis/TargetTransformInfo.h

@@ -21,7 +21,6 @@
 #ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFO_H
 #define LLVM_ANALYSIS_TARGETTRANSFORMINFO_H
 
-#include "llvm/Analysis/IVDescriptors.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/PassManager.h"
@@ -54,6 +53,7 @@ class LoopAccessInfo;
 class Loop;
 class LoopInfo;
 class ProfileSummaryInfo;
+class RecurrenceDescriptor;
 class SCEV;
 class ScalarEvolution;
 class StoreInst;

llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp

@@ -9,6 +9,7 @@
 #include "AArch64TargetTransformInfo.h"
 #include "AArch64ExpandImm.h"
 #include "MCTargetDesc/AArch64AddressingModes.h"
+#include "llvm/Analysis/IVDescriptors.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/CodeGen/BasicTTIImpl.h"

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h

@@ -18,6 +18,7 @@
 
 #include "RISCVSubtarget.h"
 #include "RISCVTargetMachine.h"
+#include "llvm/Analysis/IVDescriptors.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/CodeGen/BasicTTIImpl.h"
 #include "llvm/IR/Function.h"