[FIR] Ignore the operator keyword when checking conflicting overloads

^KT-59880

compiler/testData/diagnostics/tests/dataClasses/conflictingOverloads.fir.kt

@@ -1,4 +1,4 @@
-data class A(val x: Int, val y: String) {
-    fun component1() = 1
-    fun component2() = 2
+data class <!CONFLICTING_OVERLOADS, CONFLICTING_OVERLOADS!>A(val x: Int, val y: String)<!> {
+    <!CONFLICTING_OVERLOADS!>fun component1()<!> = 1
+    <!CONFLICTING_OVERLOADS!>fun component2()<!> = 2
 }