Minor, move tests on JvmField into subdirectory

compiler/testData/codegen/box/reflection/properties/jvmField/interfaceCompanion.kt

@@ -0,0 +1,25 @@
+// !LANGUAGE: +JvmFieldInInterface
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JS
+// IGNORE_BACKEND: JS_IR
+// WITH_REFLECT
+
+import kotlin.reflect.KProperty1
+import kotlin.reflect.full.memberProperties
+import kotlin.reflect.full.companionObject
+
+class Bar(val value: String)
+
+interface Foo {
+
+    companion object {
+        @JvmField
+        val z = Bar("OK")
+    }
+}
+
+
+fun box(): String {
+    val field = Foo::class.companionObject!!.memberProperties.single() as KProperty1<Foo.Companion, Bar>
+    return field.get(Foo.Companion).value
+}