Fix wrong nullability enhancement for annotated java.lang.Object type

Effectively, this commit drops cached value for j.l.Object type
This cache was introduced when types were immutable, but they
became mutable after starting reading top-level TYPE_USE annotations,
that lead to changing shared JAVA_LANG_OBJECT_CLASSIFIER_TYPE instance

 #KT-20826 Fixed

compiler/testData/foreignAnnotationsJava8/tests/typeUseOnObject.kt

@@ -0,0 +1,17 @@
+// FILE: A.java
+import org.checkerframework.checker.nullness.qual.*;
+public class A {
+    @NonNull
+    public Object foo() { return null; }
+}
+// FILE: B.java
+public class B {
+    public static void assertNonNull(Object x) {}
+}
+
+// FILE: main.kt
+
+fun main() {
+    A()
+    B.assertNonNull(null)
+}

compiler/testData/foreignAnnotationsJava8/tests/typeUseOnObject.txt

@@ -0,0 +1,21 @@
+package
+
+public fun main(): kotlin.Unit
+
+public open class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @org.checkerframework.checker.nullness.qual.NonNull public open fun foo(): @org.checkerframework.checker.nullness.qual.NonNull kotlin.Any
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public open class B {
+    public constructor B()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public open fun assertNonNull(/*0*/ x: kotlin.Any!): kotlin.Unit
+}