Remove dead code from GlobalISelEmitter

[kimgr]

Summary

Found by GCC's -Wunused-function.

[dsanders]

LGTM. I'm surprised the buildbots didn't report this sooner.

[kimgr]

Could you also commit this for me, I don't have commit privs. Thanks!

utils/TableGen/GlobalISelEmitter.cpp

private:
   SubtargetFeatureInfoMap SubtargetFeatures;
 
   // Rule coverage information.
   Optional<CodeGenCoverage> RuleCoverage;
 
   void gatherOpcodeValues();
   void gatherTypeIDValues();
   void gatherNodeEquivs();
-  // Instruction predicate code that will be emitted in generated functions.
-  SmallVector<std::string, 2> InstructionPredicateCodes;
-  unsigned getOrCreateInstructionPredicateFnId(StringRef Code);
 
   Record *findNodeEquiv(Record *N) const;
   const CodeGenInstruction *getEquivNode(Record &Equiv,
                                          const TreePatternNode *N) const;
 
   Error importRulePredicates(RuleMatcher &M, ArrayRef<Predicate> Predicates);
   Expected<InstructionMatcher &>
   createAndImportSelDAGMatcher(RuleMatcher &Rule,

 
 void GlobalISelEmitter::gatherOpcodeValues() {
   InstructionOpcodeMatcher::initOpcodeValuesMap(Target);
 }
 
 void GlobalISelEmitter::gatherTypeIDValues() {
   LLTOperandMatcher::initTypeIDValuesMap();
 }
-unsigned GlobalISelEmitter::getOrCreateInstructionPredicateFnId(StringRef Code) {
-  // There's not very many predicates that need to be here at the moment so we
-  // just maintain a simple set-like vector. If it grows then we'll need to do
-  // something more efficient.
-  const auto &I = std::find(InstructionPredicateCodes.begin(),
-                            InstructionPredicateCodes.end(),
-                            Code);
-  if (I == InstructionPredicateCodes.end()) {
-    unsigned ID = InstructionPredicateCodes.size();
-    InstructionPredicateCodes.push_back(Code);
-    return ID;
-  }
-  return std::distance(InstructionPredicateCodes.begin(), I);
-}
 
 void GlobalISelEmitter::gatherNodeEquivs() {
   assert(NodeEquivs.empty());
   for (Record *Equiv : RK.getAllDerivedDefinitions("GINodeEquiv"))
     NodeEquivs[Equiv->getValueAsDef("Node")] = Equiv;
 
   assert(ComplexPatternEquivs.empty());
   for (Record *Equiv : RK.getAllDerivedDefinitions("GIComplexPatternEquiv")) {