[ownership] Convert a few small visitor methods to be const.

Author: gottesmm

include/swift/SIL/OwnershipUtils.h

@@ -178,13 +178,13 @@ struct BorrowingOperand {
 
   /// Visit all of the results of the operand's user instruction that are
   /// consuming uses.
-  void visitUserResultConsumingUses(function_ref<void(Operand *)> visitor);
+  void visitUserResultConsumingUses(function_ref<void(Operand *)> visitor) const;
 
   /// Visit all of the "results" of the user of this operand that are borrow
   /// scope introducers for the specific scope that this borrow scope operand
   /// summarizes.
   void
-  visitBorrowIntroducingUserResults(function_ref<void(BorrowedValue)> visitor);
+  visitBorrowIntroducingUserResults(function_ref<void(BorrowedValue)> visitor) const;
 
   /// Passes to visitor all of the consuming uses of this use's using
   /// instruction.
@@ -193,7 +193,7 @@ struct BorrowingOperand {
   /// guaranteed scope by using a worklist and checking if any of the operands
   /// are BorrowScopeOperands.
   void visitConsumingUsesOfBorrowIntroducingUserResults(
-      function_ref<void(Operand *)> visitor);
+      function_ref<void(Operand *)> visitor) const;
 
   void print(llvm::raw_ostream &os) const;
   SWIFT_DEBUG_DUMP { print(llvm::dbgs()); }

lib/SIL/OwnershipUtils.cpp

@@ -190,7 +190,7 @@ void BorrowingOperand::visitEndScopeInstructions(
 }
 
 void BorrowingOperand::visitBorrowIntroducingUserResults(
-    function_ref<void(BorrowedValue)> visitor) {
+    function_ref<void(BorrowedValue)> visitor) const {
   switch (kind) {
   case BorrowScopeOperandKind::BeginApply:
     llvm_unreachable("Never has borrow introducer results!");
@@ -212,7 +212,7 @@ void BorrowingOperand::visitBorrowIntroducingUserResults(
 }
 
 void BorrowingOperand::visitConsumingUsesOfBorrowIntroducingUserResults(
-    function_ref<void(Operand *)> func) {
+    function_ref<void(Operand *)> func) const {
   // First visit all of the results of our user that are borrow introducing
   // values.
   visitBorrowIntroducingUserResults([&](BorrowedValue value) {
@@ -238,7 +238,7 @@ void BorrowingOperand::visitConsumingUsesOfBorrowIntroducingUserResults(
 }
 
 void BorrowingOperand::visitUserResultConsumingUses(
-    function_ref<void(Operand *)> visitor) {
+    function_ref<void(Operand *)> visitor) const {
   auto *ti = dyn_cast<TermInst>(op->getUser());
   if (!ti) {
     for (SILValue result : op->getUser()->getResults()) {