Remove redundant SILType::isMoveOnlyNominalType (NFC)

and implement `SILType::isPureMoveOnly` in terms of `Type::isPureMoveOnly`.

Author: jckarter

include/swift/SIL/SILType.h

@@ -756,10 +756,6 @@ class SILType {
   /// deinitialization beyond destruction of its members.
   bool isValueTypeWithDeinit() const;
 
-  /// Returns true if and only if this type is a first class move only
-  /// type. NOTE: Returns false if the type is a move only wrapped type.
-  bool isMoveOnlyNominalType() const;
-
   /// Returns true if this SILType is a move only wrapper type.
   ///
   /// Canonical way to check if a SILType is move only. Using is/getAs/castTo

lib/SIL/IR/SILType.cpp

@@ -1030,7 +1030,7 @@ SILType::getSingletonAggregateFieldType(SILModule &M,
 
 bool SILType::isMoveOnly() const {
   // Nominal types are move-only if declared as such.
-  if (isMoveOnlyNominalType())
+  if (isPureMoveOnly())
     return true;
 
 
@@ -1048,20 +1048,12 @@ bool SILType::isMoveOnly() const {
   return isMoveOnlyWrapped();
 }
 
-bool SILType::isMoveOnlyNominalType() const {
-  if (auto *nom = getNominalOrBoundGenericNominal())
-    if (nom->isMoveOnly())
-      return true;
-  return false;
-}
-
 bool SILType::isPureMoveOnly() const {
-  if (auto *nom = getNominalOrBoundGenericNominal())
-    if (nom->isMoveOnly())
-      return true;
-  return false;
+  return getASTType()->isPureMoveOnly();
 }
 
+
+
 bool SILType::isValueTypeWithDeinit() const {
   // Do not look inside an aggregate type that has a user-deinit, for which
   // memberwise-destruction is not equivalent to aggregate destruction.

lib/SIL/Verifier/SILVerifier.cpp

@@ -6016,7 +6016,7 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     auto type = ddi->getType();
     require(type == ddi->getOperand()->getType(),
             "Result and operand must have the same type.");
-    require(type.isMoveOnlyNominalType(),
+    require(type.isPureMoveOnly(),
             "drop_deinit only allowed for move-only types");
     require(type.getNominalOrBoundGenericNominal()
             ->getValueTypeDestructor(), "drop_deinit only allowed for "

lib/SILOptimizer/Transforms/MoveOnlyDeinitDevirtualization.cpp

@@ -69,11 +69,15 @@ static bool performTransform(SILFunction &fn) {
 
       if (auto *dvi = dyn_cast<DestroyValueInst>(inst)) {
         auto destroyType = dvi->getOperand()->getType();
-        if (destroyType.isMoveOnlyNominalType() &&
+        if (destroyType.isPureMoveOnly() &&
             !isa<DropDeinitInst>(lookThroughOwnershipInsts(dvi->getOperand()))) {
           LLVM_DEBUG(llvm::dbgs() << "Handling: " << *dvi);
           auto *nom = destroyType.getNominalOrBoundGenericNominal();
-          assert(nom);
+          if (!nom) {
+            LLVM_DEBUG(llvm::dbgs()
+                       << "Not a nominal type, so no deinit! Skipping!\n");
+            continue;
+          }
           auto *deinitFunc = mod.lookUpMoveOnlyDeinitFunction(nom);
           if (!deinitFunc) {
             LLVM_DEBUG(llvm::dbgs()
@@ -108,11 +112,15 @@ static bool performTransform(SILFunction &fn) {
 
       if (auto *dai = dyn_cast<DestroyAddrInst>(inst)) {
         auto destroyType = dai->getOperand()->getType();
-        if (destroyType.isLoadable(fn) && destroyType.isMoveOnlyNominalType() &&
+        if (destroyType.isLoadable(fn) && destroyType.isPureMoveOnly() &&
             !isa<DropDeinitInst>(dai->getOperand())) {
           LLVM_DEBUG(llvm::dbgs() << "Handling: " << *dai);
           auto *nom = destroyType.getNominalOrBoundGenericNominal();
-          assert(nom);
+          if (!nom) {
+            LLVM_DEBUG(llvm::dbgs()
+                       << "Not a nominal type, so no deinit! Skipping!\n");
+            continue;
+          }
           auto *deinitFunc = mod.lookUpMoveOnlyDeinitFunction(nom);
           if (!deinitFunc) {
             LLVM_DEBUG(llvm::dbgs()