Clean up.

Author: dan-zheng

lib/SILGen/SILGen.cpp

@@ -811,7 +811,6 @@ void SILGenModule::emitDifferentiabilityWitness(
   };
   bool reorderSelf = shouldReorderSelf();
 
-  // Get or create differentiability witness.
   CanGenericSignature derivativeCanGenSig;
   if (auto *derivativeGenSig = config.derivativeGenericSignature)
     derivativeCanGenSig = derivativeGenSig->getCanonicalSignature();

lib/Serialization/SerializeSIL.cpp

@@ -2322,7 +2322,7 @@ void SILSerializer::writeIndexTables() {
   }
 
   // SWIFT_ENABLE_TENSORFLOW
-  if (!DifferentiabilityWitnessOffset.empty()) {
+  if (!DifferentiabilityWitnessList.empty()) {
     writeIndexTable(S, List,
                     sil_index_block::SIL_DIFFERENTIABILITY_WITNESS_NAMES,
                     DifferentiabilityWitnessList);
@@ -2542,17 +2542,12 @@ writeSILDifferentiabilityWitness(const SILDifferentiabilityWitness &dw) {
   DifferentiabilityWitnessOffset.push_back(Out.GetCurrentBitNo());
 
   auto *original = dw.getOriginalFunction();
-  addReferencedSILFunction(original, /*DeclOnly*/ true);
   IdentifierID jvpID = 0;
   IdentifierID vjpID = 0;
-  if (auto *jvp = dw.getJVP()) {
-    addReferencedSILFunction(jvp, /*DeclOnly*/ true);
-    jvpID = S.addUniquedStringRef(jvp->getName());
-  }
-  if (auto *vjp = dw.getVJP()) {
-    addReferencedSILFunction(vjp, /*DeclOnly*/ true);
-    vjpID = S.addUniquedStringRef(vjp->getName());
-  }
+  if (auto *jvp = dw.getJVP())
+    jvpID = addSILFunctionRef(jvp);
+  if (auto *vjp = dw.getVJP())
+    vjpID = addSILFunctionRef(vjp);
   SmallVector<unsigned, 8> parameterAndResultIndices(
       dw.getParameterIndices()->begin(), dw.getParameterIndices()->end());
   parameterAndResultIndices.append(dw.getResultIndices()->begin(),
@@ -2569,7 +2564,7 @@ writeSILDifferentiabilityWitness(const SILDifferentiabilityWitness &dw) {
 
   DifferentiabilityWitnessLayout::emitRecord(
       Out, ScratchRecord, SILAbbrCodes[DifferentiabilityWitnessLayout::Code],
-      S.addUniquedStringRef(original->getName()),
+      addSILFunctionRef(original),
       toStableSILLinkage(dw.getLinkage()),
       dw.isSerialized(),
       S.addGenericSignatureRef(dw.getDerivativeGenericSignature()),