JVM IR: don't rename fake overrides for fields

In case derived class has a field with the same name as the base class,
RenameFieldsLowering previously tried to rename one of the fields by
adding the "...$1" suffix, which led to NoSuchFieldError.

compiler/testData/codegen/box/jvmField/clashWithJavaSuperClassField.kt

@@ -0,0 +1,19 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+// FILE: test.kt
+
+abstract class A {
+    @JvmField
+    protected var flag: String = "Fail"
+}
+
+fun box(): String = object : J() {
+    val result = flag
+}.result
+
+// FILE: J.java
+
+public class J extends A {
+    protected String flag = "OK";
+}