SIL: Use getDefinedOpenedArchetype() to simplify SILCloner

Author: slavapestov

include/swift/SIL/SILCloner.h

@@ -2675,7 +2675,7 @@ template<typename ImplClass>
 void
 SILCloner<ImplClass>::visitOpenExistentialAddrInst(OpenExistentialAddrInst *Inst) {
   // Create a new archetype for this opened existential type.
-  remapRootOpenedType(Inst->getType().castTo<OpenedArchetypeType>());
+  remapRootOpenedType(Inst->getDefinedOpenedArchetype());
 
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   recordClonedInstruction(
@@ -2688,7 +2688,7 @@ template <typename ImplClass>
 void SILCloner<ImplClass>::visitOpenExistentialValueInst(
     OpenExistentialValueInst *Inst) {
   // Create a new archetype for this opened existential type.
-  remapRootOpenedType(Inst->getType().castTo<OpenedArchetypeType>());
+  remapRootOpenedType(Inst->getDefinedOpenedArchetype());
 
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   recordClonedInstruction(
@@ -2704,14 +2704,7 @@ template<typename ImplClass>
 void
 SILCloner<ImplClass>::
 visitOpenExistentialMetatypeInst(OpenExistentialMetatypeInst *Inst) {
-  // Create a new archetype for this opened existential type.
-  auto openedType = Inst->getType().getASTType();
-  auto exType = Inst->getOperand()->getType().getASTType();
-  while (auto exMetatype = dyn_cast<ExistentialMetatypeType>(exType)) {
-    exType = exMetatype->getExistentialInstanceType()->getCanonicalType();
-    openedType = cast<MetatypeType>(openedType).getInstanceType();
-  }
-  remapRootOpenedType(cast<OpenedArchetypeType>(openedType));
+  remapRootOpenedType(Inst->getDefinedOpenedArchetype());
 
   if (!Inst->getOperand()->getType().canUseExistentialRepresentation(
           ExistentialRepresentation::Class)) {
@@ -2735,7 +2728,7 @@ void
 SILCloner<ImplClass>::
 visitOpenExistentialRefInst(OpenExistentialRefInst *Inst) {
   // Create a new archetype for this opened existential type.
-  remapRootOpenedType(Inst->getType().castTo<OpenedArchetypeType>());
+  remapRootOpenedType(Inst->getDefinedOpenedArchetype());
 
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   recordClonedInstruction(
@@ -2752,7 +2745,7 @@ void
 SILCloner<ImplClass>::
 visitOpenExistentialBoxInst(OpenExistentialBoxInst *Inst) {
   // Create a new archetype for this opened existential type.
-  remapRootOpenedType(Inst->getType().castTo<OpenedArchetypeType>());
+  remapRootOpenedType(Inst->getDefinedOpenedArchetype());
 
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   recordClonedInstruction(Inst, getBuilder().createOpenExistentialBox(
@@ -2766,7 +2759,7 @@ void
 SILCloner<ImplClass>::
 visitOpenExistentialBoxValueInst(OpenExistentialBoxValueInst *Inst) {
   // Create a new archetype for this opened existential type.
-  remapRootOpenedType(Inst->getType().castTo<OpenedArchetypeType>());
+  remapRootOpenedType(Inst->getDefinedOpenedArchetype());
 
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
   recordClonedInstruction(