[Stubs] Fix stub inconsistency on unnamed setter parameters

If an unused setter parameter was replaced with an underscore ('_'),
it had a special name in the stub ('<anonymous parameter 0>'). The text
version of the stub inserted it as is, leading to an extra
'PsiErrorElement'.

^KTIJ-28194 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java

@@ -42,6 +42,7 @@ import org.jetbrains.kotlin.diagnostics.Errors;
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation;
 import org.jetbrains.kotlin.lexer.KtTokens;
 import org.jetbrains.kotlin.name.Name;
+import org.jetbrains.kotlin.name.SpecialNames;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.psi.psiUtil.PsiUtilsKt;
 import org.jetbrains.kotlin.resolve.calls.components.InferenceSession;
@@ -366,7 +367,7 @@ public class DescriptorResolver {
             // of containing class where, it can not find a descriptor with special name.
             // Thus, to preserve behavior, we don't use a special name for val/var.
             parameterName = !valueParameter.hasValOrVar() && UnderscoreUtilKt.isSingleUnderscore(valueParameter)
-                            ? Name.special("<anonymous parameter " + index + ">")
+                            ? SpecialNames.anonymousParameterName(index)
                             : KtPsiUtil.safeName(valueParameter.getName());
         }
         else {