Replace 'addOverriddenDescriptor' with 'setOverriddenDescriptors'

It helps to get rid of redundant SmartSets (e.g. for top-level functions)

compiler/backend/src/org/jetbrains/kotlin/codegen/ClosureCodegen.java

@@ -195,7 +195,7 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
                                 erasedInterfaceFunction.getValueParameters(), erasedInterfaceFunction.getReturnType(),
                                 Modality.OPEN, erasedInterfaceFunction.getVisibility());
 
-            descriptorForBridges.addOverriddenDescriptor(erasedInterfaceFunction);
+            DescriptorUtilsKt.setSingleOverridden(descriptorForBridges, erasedInterfaceFunction);
             functionCodegen.generateBridges(descriptorForBridges);
         }
 

compiler/backend/src/org/jetbrains/kotlin/codegen/SamWrapperCodegen.java

@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.KtFile;
 import org.jetbrains.kotlin.resolve.DescriptorUtils;
+import org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt;
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOriginKt;
 import org.jetbrains.kotlin.types.KotlinType;
 import org.jetbrains.kotlin.util.OperatorNameConventions;
@@ -165,7 +166,7 @@ public class SamWrapperCodegen {
                             originalInterfaceErased.getValueParameters(), originalInterfaceErased.getReturnType(),
                             Modality.OPEN, originalInterfaceErased.getVisibility());
 
-        descriptorForBridges.addOverriddenDescriptor(originalInterfaceErased);
+        DescriptorUtilsKt.setSingleOverridden(descriptorForBridges, originalInterfaceErased);
         codegen.generateBridges(descriptorForBridges);
     }