Find Usages: Skip overriden descriptors which have no corresponding declaration (EA-58371)

idea/testData/findUsages/kotlin/findFunctionUsages/synthesizedFunction.0.kt

@@ -0,0 +1,13 @@
+// PSI_ELEMENT: org.jetbrains.jet.lang.psi.JetNamedFunction
+// OPTIONS: usages, skipImports
+
+open data class A(val a: Int)
+
+class B(b: Int): A(b) {
+    override fun <caret>copy(b: Int): B = B(b)
+}
+
+fun main(a: A) {
+    a.copy(1)
+    B(0).copy(1)
+}

idea/testData/findUsages/kotlin/findFunctionUsages/synthesizedFunction.results.txt

@@ -0,0 +1 @@
+Function call (12: 10) B(0).copy(1)