[sil] Add getOperand() variants for pack instructions.

We already had getValue() variants... this just expands those to operands. The
reason why this is useful is that these instructions have specific operands with
specific meanings as assigned by an internal enum struct. Rather than having to
access those directly by using getAllOperand()[EnumCase]... better to have a
named method.

Author: gottesmm

include/swift/SIL/SILInstruction.h

@@ -7983,12 +7983,20 @@ class PackElementGetInst final
                                     SILType elementType);
 
 public:
-  SILValue getIndex() const {
-    return getAllOperands()[IndexOperand].get();
+  SILValue getIndex() const { return getIndexOperand()->get(); }
+
+  Operand *getIndexOperand() { return &getAllOperands()[IndexOperand]; }
+
+  const Operand *getIndexOperand() const {
+    return &getAllOperands()[IndexOperand];
   }
 
-  SILValue getPack() const {
-    return getAllOperands()[PackOperand].get();
+  SILValue getPack() const { return getPackOperand()->get(); }
+
+  Operand *getPackOperand() { return &getAllOperands()[PackOperand]; }
+
+  const Operand *getPackOperand() const {
+    return &getAllOperands()[PackOperand];
   }
 
   CanSILPackType getPackType() const {
@@ -8028,18 +8036,29 @@ class PackElementSetInst
   ArrayRef<Operand> getAllOperands() const { return Operands.asArray(); }
   MutableArrayRef<Operand> getAllOperands() { return Operands.asArray(); }
 
-  SILValue getValue() const {
-    return getAllOperands()[ValueOperand].get();
+  SILValue getValue() const { return getValueOperand()->get(); }
+
+  const Operand *getValueOperand() const {
+    return &getAllOperands()[ValueOperand];
   }
 
-  SILValue getIndex() const {
-    return getAllOperands()[IndexOperand].get();
+  Operand *getValueOperand() { return &getAllOperands()[ValueOperand]; }
+
+  SILValue getIndex() const { return getIndexOperand()->get(); }
+
+  const Operand *getIndexOperand() const {
+    return &getAllOperands()[IndexOperand];
   }
+  Operand *getIndexOperand() { return &getAllOperands()[IndexOperand]; }
+
+  SILValue getPack() const { return getPackOperand()->get(); }
 
-  SILValue getPack() const {
-    return getAllOperands()[PackOperand].get();
+  const Operand *getPackOperand() const {
+    return &getAllOperands()[PackOperand];
   }
 
+  Operand *getPackOperand() { return &getAllOperands()[PackOperand]; }
+
   CanSILPackType getPackType() const {
     return getPack()->getType().castTo<SILPackType>();
   }
@@ -8079,12 +8098,20 @@ class TuplePackElementAddrInst final
                                           SILType elementType);
 
 public:
-  SILValue getIndex() const {
-    return getAllOperands()[IndexOperand].get();
+  SILValue getIndex() const { return getIndexOperand()->get(); }
+
+  Operand *getIndexOperand() { return &getAllOperands()[IndexOperand]; }
+
+  const Operand *getIndexOperand() const {
+    return &getAllOperands()[IndexOperand];
   }
 
-  SILValue getTuple() const {
-    return getAllOperands()[TupleOperand].get();
+  SILValue getTuple() const { return getTupleOperand()->get(); }
+
+  Operand *getTupleOperand() { return &getAllOperands()[TupleOperand]; }
+
+  const Operand *getTupleOperand() const {
+    return &getAllOperands()[TupleOperand];
   }
 
   CanTupleType getTupleType() const {
@@ -8124,9 +8151,21 @@ class TuplePackExtractInst final
          ValueOwnershipKind forwardingOwnershipKind);
 
 public:
-  SILValue getIndex() const { return getAllOperands()[IndexOperand].get(); }
+  SILValue getIndex() const { return getIndexOperand()->get(); }
 
-  SILValue getTuple() const { return getAllOperands()[TupleOperand].get(); }
+  Operand *getIndexOperand() { return &getAllOperands()[IndexOperand]; }
+
+  const Operand *getIndexOperand() const {
+    return &getAllOperands()[IndexOperand];
+  }
+
+  SILValue getTuple() const { return getTupleOperand()->get(); }
+
+  Operand *getTupleOperand() { return &getAllOperands()[TupleOperand]; }
+
+  const Operand *getTupleOperand() const {
+    return &getAllOperands()[TupleOperand];
+  }
 
   CanTupleType getTupleType() const {
     return getTuple()->getType().castTo<TupleType>();