[SILCloner] Remap debug variable type and scope at the same time (NFC)

(cherry picked from commit 5512df5)

Author: Snowy1803

include/swift/SIL/SILCloner.h

@@ -338,14 +338,16 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
     registerLocalArchetypeRemapping(archetypeTy, replacementTy);
   }
 
-  // SILCloner will take care of debug scope on the instruction
-  // and this helper will remap the auxiliary debug scope too, if there is any.
-  void remapDebugVarInfo(DebugVarCarryingInst DbgVarInst) {
-    if (!DbgVarInst)
+  /// SILCloner will take care of debug scope on the instruction
+  /// and this helper will remap the auxiliary debug scope too, if there is any.
+  void remapDebugVariable(std::optional<SILDebugVariable> &VarInfo) {
+    if (!VarInfo)
       return;
-    auto VarInfo = DbgVarInst.getVarInfo();
-    if (VarInfo && VarInfo->Scope)
-      DbgVarInst.setDebugVarScope(getOpScope(VarInfo->Scope));
+    if (VarInfo->Type)
+      VarInfo->Type = getOpType(*VarInfo->Type);
+    // Don't remap locations for debug values.
+    if (VarInfo->Scope)
+      VarInfo->Scope = getOpScope(VarInfo->Scope);
   }
 
   ProtocolConformanceRef getOpConformance(Type ty,
@@ -879,8 +881,7 @@ SILCloner<ImplClass>::visitAllocStackInst(AllocStackInst *Inst) {
     Loc = MandatoryInlinedLocation::getAutoGeneratedLocation();
     VarInfo = std::nullopt;
   }
-  if (VarInfo && VarInfo->Type)
-    VarInfo->Type = getOpType(*VarInfo->Type);
+  remapDebugVariable(VarInfo);
   auto *NewInst = getBuilder().createAllocStack(
       Loc, getOpType(Inst->getElementType()), VarInfo,
       Inst->hasDynamicLifetime(), Inst->isLexical(), Inst->isFromVarDecl(),
@@ -890,7 +891,6 @@ SILCloner<ImplClass>::visitAllocStackInst(AllocStackInst *Inst) {
       true
 #endif
   );
-  remapDebugVarInfo(DebugVarCarryingInst(NewInst));
   recordClonedInstruction(Inst, NewInst);
 }
 
@@ -1412,14 +1412,12 @@ SILCloner<ImplClass>::visitDebugValueInst(DebugValueInst *Inst) {
     return;
 
   // Since we want the debug info to survive, we do not remap the location here.
-  SILDebugVariable VarInfo = *Inst->getVarInfo();
+  std::optional<SILDebugVariable> VarInfo = Inst->getVarInfo();
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
-  if (VarInfo.Type)
-    VarInfo.Type = getOpType(*VarInfo.Type);
+  remapDebugVariable(VarInfo);
   auto *NewInst = getBuilder().createDebugValue(
-      Inst->getLoc(), getOpValue(Inst->getOperand()), VarInfo,
+      Inst->getLoc(), getOpValue(Inst->getOperand()), *VarInfo,
       Inst->poisonRefs(), Inst->usesMoveableValueDebugInfo(), Inst->hasTrace());
-  remapDebugVarInfo(DebugVarCarryingInst(NewInst));
   recordClonedInstruction(Inst, NewInst);
 }
 template<typename ImplClass>