Deprecate public access to @JvmField/const fields in private companions

#KT-25009

compiler/testData/codegen/bytecodeListing/privateCompanionFields.kt

@@ -0,0 +1,32 @@
+// WITH_RUNTIME
+class TestClass {
+
+    private companion object {
+        @JvmField
+        var test: String = "1"
+
+        @JvmField
+        @java.lang.Deprecated
+        var test2: String = "2"
+
+        @JvmField
+        val test3: String = "3"
+
+        const val testConst = 1
+    }
+}
+
+interface TestConst {
+
+    private companion object {
+        const val testConst = 1
+    }
+}
+
+interface TestJvmField {
+
+    private companion object {
+        @JvmField
+        val test3: String = "3"
+    }
+}