Minor, move tests about Java field and Kotlin property

Because the `fieldRename` directory was originally about cases when
private fields are renamed because of clashes.

compiler/testData/codegen/box/javaFieldAndKotlinProperty/javaFieldAndKotlinProperty.kt

@@ -0,0 +1,25 @@
+// TARGET_BACKEND: JVM_IR
+// IGNORE_BACKEND_K1: JVM_IR
+// Field VS property: case 4.1
+// See KT-50082
+// DUMP_IR
+
+// FILE: BaseJava.java
+public class BaseJava {
+    public String a = "FAIL";
+}
+
+// FILE: Derived.kt
+class Derived : BaseJava() {
+    var a = "OK"
+}
+
+fun box(): String {
+    val first = Derived().a
+    if (first != "OK") return first
+    val d = Derived()
+    if (d::a.get() != "OK") return d::a.get()
+    d.a = "12"
+    if (d.a != "12") return "Error writing: ${d.a}"
+    return "OK"
+}