Fix isTriviallyDuplicatable to handle open_pack_element

SILInstruction::clone doesn't know how to clone instructions that produce
the archetype uuid. SILCloner is equipped to handle such instructions.

Optimizations like LoopRotate use  SILInstruction::clone and will be
incorrect for such instructions.

rdar://130047619

Author: meg-gupta

lib/SIL/IR/SILInstruction.cpp

@@ -1418,8 +1418,10 @@ bool SILInstruction::isTriviallyDuplicatable() const {
 
   if (isa<OpenExistentialAddrInst>(this) || isa<OpenExistentialRefInst>(this) ||
       isa<OpenExistentialMetatypeInst>(this) ||
-      isa<OpenExistentialValueInst>(this) || isa<OpenExistentialBoxInst>(this) ||
-      isa<OpenExistentialBoxValueInst>(this)) {
+      isa<OpenExistentialValueInst>(this) ||
+      isa<OpenExistentialBoxInst>(this) ||
+      isa<OpenExistentialBoxValueInst>(this) ||
+      isa<OpenPackElementInst>(this)) {
     // Don't know how to duplicate these properly yet. Inst.clone() per
     // instruction does not work. Because the follow-up instructions need to
     // reuse the same archetype uuid which would only work if we used a

lib/SILOptimizer/Utils/LoopUtils.cpp

@@ -280,9 +280,9 @@ bool swift::canDuplicateLoopInstruction(SILLoop *L, SILInstruction *I) {
 
   // We can't have a phi of two openexistential instructions of different UUID.
   if (isa<OpenExistentialAddrInst>(I) || isa<OpenExistentialRefInst>(I) ||
-      isa<OpenExistentialMetatypeInst>(I) ||
-      isa<OpenExistentialValueInst>(I) || isa<OpenExistentialBoxInst>(I) ||
-      isa<OpenExistentialBoxValueInst>(I)) {
+      isa<OpenExistentialMetatypeInst>(I) || isa<OpenExistentialValueInst>(I) ||
+      isa<OpenExistentialBoxInst>(I) || isa<OpenExistentialBoxValueInst>(I) ||
+      isa<OpenPackElementInst>(I)) {
     SingleValueInstruction *OI = cast<SingleValueInstruction>(I);
     for (auto *UI : OI->getUses())
       if (!L->contains(UI->getUser()))