[NFC][TableGen] Adopt Emitter::OptClass in InstrInfoEmitter (llvm#125971)

- Use `Emitter::OptClass` to invoke `InstrInfoEmitter::run` and
eliminate the `EmitInstrInfo` function.

Author: jurahul

llvm/utils/TableGen/InstrInfoEmitter.cpp

@@ -890,6 +890,9 @@ void InstrInfoEmitter::emitTIIHelperMethods(raw_ostream &OS,
 
 // run - Emit the main instruction description records for the target...
 void InstrInfoEmitter::run(raw_ostream &OS) {
+  TGTimer &Timer = Records.getTimer();
+  Timer.startTimer("Analyze DAG patterns");
+
   emitSourceFileHeader("Target Instruction Enum Values and Descriptors", OS);
   emitEnums(OS);
 
@@ -898,7 +901,6 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
   const Record *InstrInfo = Target.getInstructionSet();
 
   // Collect all of the operand info records.
-  TGTimer &Timer = Records.getTimer();
   Timer.startTimer("Collect operand info");
   OperandInfoListTy OperandInfoList;
   OperandInfoMapTy OperandInfoMap;
@@ -1138,6 +1140,9 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
 
   Timer.startTimer("Emit verifier methods");
   emitFeatureVerifier(OS, Target);
+
+  Timer.startTimer("Emit map table");
+  EmitMapTable(Records, OS);
 }
 
 void InstrInfoEmitter::emitRecord(
@@ -1314,13 +1319,5 @@ void InstrInfoEmitter::emitEnums(raw_ostream &OS) {
   OS << "#endif // GET_INSTRINFO_SCHED_ENUM\n\n";
 }
 
-static void EmitInstrInfo(const RecordKeeper &Records, raw_ostream &OS) {
-  TGTimer &Timer = Records.getTimer();
-  Timer.startTimer("Analyze DAG patterns");
-  InstrInfoEmitter(Records).run(OS);
-  Timer.startTimer("Emit map table");
-  EmitMapTable(Records, OS);
-}
-
-static TableGen::Emitter::Opt X("gen-instr-info", EmitInstrInfo,
-                                "Generate instruction descriptions");
+static TableGen::Emitter::OptClass<InstrInfoEmitter>
+    X("gen-instr-info", "Generate instruction descriptions");