Use unchecked_ownership during SILGen of borrow accessors

Author: meg-gupta

lib/SILGen/SILGenApply.cpp

@@ -5479,6 +5479,13 @@ ManagedValue SILGenFunction::applyBorrowMutateAccessor(
   assert(rawResults.size() == 1);
   auto rawResult = rawResults[0];
 
+  if (fn.getFunction()->getConventions().hasGuaranteedResult()) {
+    auto selfArg = args.back().getValue();
+    if (isa<LoadBorrowInst>(selfArg)) {
+      rawResult = B.createUncheckedOwnership(loc, rawResult);
+    }
+  }
+
   if (rawResult->getType().isMoveOnly()) {
     if (rawResult->getType().isAddress()) {
       auto result = B.createMarkUnresolvedNonCopyableValueInst(

lib/SILGen/SILGenStmt.cpp

@@ -719,7 +719,8 @@ bool SILGenFunction::emitBorrowOrMutateAccessorResult(
     assert(guaranteedAddress.getValue()->getType().isAddress());
     assert(F.getConventions().hasGuaranteedResult());
     auto regularLoc = RegularLocation::getAutoGeneratedLocation();
-    return B.createLoadBorrow(regularLoc, guaranteedAddress).getValue();
+    auto load = B.createLoadBorrow(regularLoc, guaranteedAddress).getValue();
+    return B.createUncheckedOwnership(regularLoc, load);
   };
 
   // If the return expression is a literal, emit as a regular return