[LLVM][NFC] remove unused fields

[gchatelet]

Summary

Here is the commit introducing the fields
https://github.com/llvm/llvm-project/commit/cf6749e4c091

It dates back from 2006 and was used by AArch64 backend.
There is no more reference to these fields in the whole codebase so I think it's fine.

llvm/include/llvm/CodeGen/BasicTTIImpl.h

if (IsJTAllowed) {
       if (TLI->isSuitableForJumpTable(&SI, N, Range)) {
         JumpTableSize = Range;
         return 1;
       }
     }
     return N;
   }
 
-  unsigned getJumpBufAlignment() { return getTLI()->getJumpBufAlignment(); }
-
-  unsigned getJumpBufSize() { return getTLI()->getJumpBufSize(); }
-
   bool shouldBuildLookupTables() {
     const TargetLoweringBase *TLI = getTLI();
     return TLI->isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
            TLI->isOperationLegalOrCustom(ISD::BRIND, MVT::Other);
   }
 
   bool haveFastSqrt(Type *Ty) {
     const TargetLoweringBase *TLI = getTLI();

llvm/include/llvm/CodeGen/TargetLowering.h

getExceptionSelectorRegister(const Constant *PersonalityFn) const {
     // 0 is guaranteed to be the NoRegister value on all targets
     return 0;
   }
 
   virtual bool needsFixedCatchObjects() const {
     report_fatal_error("Funclet EH is not implemented for this target");
   }
 
-  /// Returns the target's jmp_buf size in bytes (if never set, the default is
-  /// 200)
-  unsigned getJumpBufSize() const {
-    return JumpBufSize;
-  }
-
-  /// Returns the target's jmp_buf alignment in bytes (if never set, the default
-  /// is 0)
-  unsigned getJumpBufAlignment() const {
-    return JumpBufAlignment;
-  }
-
   /// Return the minimum stack alignment of an argument.
   unsigned getMinStackArgumentAlignment() const {
     return MinStackArgumentAlignment;
   }
 
   /// Return the minimum function alignment.
   unsigned getMinFunctionAlignment() const {
     return MinFunctionAlignment;
protected:
   /// Targets should invoke this method for each target independent node that
   /// they want to provide a custom DAG combiner for by implementing the
   /// PerformDAGCombine virtual method.
   void setTargetDAGCombine(ISD::NodeType NT) {
     assert(unsigned(NT >> 3) < array_lengthof(TargetDAGCombineArray));
     TargetDAGCombineArray[NT >> 3] |= 1 << (NT&7);
   }
 
-  /// Set the target's required jmp_buf buffer size (in bytes); default is 200
-  void setJumpBufSize(unsigned Size) {
-    JumpBufSize = Size;
-  }
-
-  /// Set the target's required jmp_buf buffer alignment (in bytes); default is
-  /// 0
-  void setJumpBufAlignment(unsigned Align) {
-    JumpBufAlignment = Align;
-  }
-
   /// Set the target's minimum function alignment (in log2(bytes))
   void setMinFunctionAlignment(unsigned Align) {
     MinFunctionAlignment = Align;
   }
 
   /// Set the target's preferred function alignment.  This should be set if
   /// there is a performance benefit to higher-than-minimum alignment (in
   /// log2(bytes))
private:
   /// Information about the contents of the high-bits in boolean vector values
   /// when the element type is wider than i1. See getBooleanContents.
   BooleanContent BooleanVectorContents;
 
   /// The target scheduling preference: shortest possible total cycles or lowest
   /// register usage.
   Sched::Preference SchedPreferenceInfo;
 
-  /// The size, in bytes, of the target's jmp_buf buffers
-  unsigned JumpBufSize;
-
-  /// The alignment, in bytes, of the target's jmp_buf buffers
-  unsigned JumpBufAlignment;
-
   /// The minimum alignment that any argument on the stack needs to have.
   unsigned MinStackArgumentAlignment;
 
   /// The minimum function alignment (used when optimizing for size, and to
   /// prevent explicitly provided alignment from leading to incorrect code).
   unsigned MinFunctionAlignment;
 
   /// The preferred function alignment (used when alignment unspecified and

llvm/lib/CodeGen/TargetLoweringBase.cpp

TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
   JumpIsExpensive = JumpIsExpensiveOverride;
   PredictableSelectIsExpensive = false;
   EnableExtLdPromotion = false;
   StackPointerRegisterToSaveRestore = 0;
   BooleanContents = UndefinedBooleanContent;
   BooleanFloatContents = UndefinedBooleanContent;
   BooleanVectorContents = UndefinedBooleanContent;
   SchedPreferenceInfo = Sched::ILP;
-  JumpBufSize = 0;
-  JumpBufAlignment = 0;
   MinFunctionAlignment = 0;
   PrefFunctionAlignment = 0;
   PrefLoopAlignment = 0;
   GatherAllAliasesMaxDepth = 18;
   MinStackArgumentAlignment = 1;
   // TODO: the default will be switched to 0 in the next commit, along
   // with the Target-specific changes necessary.
   MaxAtomicSizeInBitsSupported = 1024;