sil: load [copy] affects reference counting

Based on what I see from OwnershipModelEliminator,
`%x = load [copy] %y` can turn into a plain load
followed by a retain of the loaded value.

See `NonTrivialLoadableTypeLowering::emitLoad`

docs/SIL/Instructions.md

@@ -832,7 +832,7 @@ load-ownership-kind ::= 'take'
 ```
 
 Loads the value at address `%0` from memory. `T` must be a loadable
-type. This does not affect the reference count, if any, of the loaded
+type. An unqualified load does not affect the reference count, if any, of the loaded
 value; the value must be retained explicitly if necessary. It is
 undefined behavior to load from uninitialized memory or to load from an
 address that points to deallocated storage.
@@ -840,8 +840,8 @@ address that points to deallocated storage.
 In OSSA the ownership kind specifies how to handle ownership:
 -  **trivial**: the loaded value is trivial and no further action must be taken
                 than to load the raw bits of the value
--  **copy**: the loaded value is copied and the original value stays in the
-             memory location.
+-  **copy**: the loaded value is copied (e.g., retained) and the original value
+                stays in the memory location.
 -  **take**: the value is _moved_ from the memory location without copying.
              After the `load`, the memory location remains uninitialized.
 

lib/SIL/Utils/InstructionUtils.cpp

@@ -552,7 +552,6 @@ RuntimeEffect swift::getRuntimeEffect(SILInstruction *inst, SILType &impactType)
   case SILInstructionKind::CopyableToMoveOnlyWrapperValueInst:
   case SILInstructionKind::MoveOnlyWrapperToCopyableValueInst:
   case SILInstructionKind::UncheckedOwnershipConversionInst:
-  case SILInstructionKind::LoadInst:
   case SILInstructionKind::LoadBorrowInst:
   case SILInstructionKind::BeginBorrowInst:
   case SILInstructionKind::BorrowedFromInst:
@@ -626,6 +625,14 @@ RuntimeEffect swift::getRuntimeEffect(SILInstruction *inst, SILType &impactType)
   case SILInstructionKind::TypeValueInst:
   case SILInstructionKind::IgnoredUseInst:
     return RuntimeEffect::NoEffect;
+
+  case SILInstructionKind::LoadInst: {
+    if (cast<LoadInst>(inst)->getOwnershipQualifier() == LoadOwnershipQualifier::Copy) {
+      return ifNonTrivial(inst->getOperand(0)->getType(),
+                          RuntimeEffect::RefCounting);
+    }
+    return RuntimeEffect::NoEffect;
+  }
       
   case SILInstructionKind::OpenExistentialMetatypeInst:
   case SILInstructionKind::OpenExistentialBoxInst: