JShell does not work correctly when a class named Object or Throwable is defined

A DESCRIPTION OF THE PROBLEM :
In JShell, after a class named Object is defined, it will not create any type of scratch variables except this "Object" class, including java.lang.Object and primitive types. Any attempt to create a scratch variable or call a non-void function will either fail with an error message "incompatible types: <type> cannot be converted to Object" or discard the value, even if the type is java.lang.Object, unless the type is the post-defined Object class.

After a class named Throwable is defined, every statement, whether it throws an exception or not, will fail with an error message "incompatible types: Throwable cannot be converted to java.lang.Throwable".

This issue does not exist for javac. In javac, java.lang.Object and java.lang.Throwable can be distinguished from the user-defined Object and Throwable type by specifying the full name `java.lang.Object` or `java.lang.Throwable`.

This issue does not exist for Iterable and AutoCloseable.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run JShell and input the test cases shown below.

ACTUAL -
It behaves like this:

#1
$ jshell -v
| Welcome to JShell -- Version 21.0.2
| For an introduction type: /help intro

jshell> class Object {}
| created class Object

jshell> 0
| Error:
| incompatible types: int cannot be converted to Object
| 0
| ^

jshell> 0.0
| Error:
| incompatible types: double cannot be converted to Object
| 0.0
| ^-^

jshell> false
| Error:
| incompatible types: boolean cannot be converted to Object
| false
| ^---^

jshell> null
$2 ==> null
| created scratch variable $2 : Object

jshell> (java.lang.Object)null
| Error:
| incompatible types: java.lang.Object cannot be converted to Object
| (java.lang.Object)null
| ^--------------------^

jshell> "string"
| Error:
| incompatible types: java.lang.String cannot be converted to Object
| "string"
| ^------^

jshell> Math.sqrt(2.0) // the return value is discarded

jshell> new Object()
$4 ==> Object@1e80bfe8
| created scratch variable $4 : Object

jshell> new java.lang.Object() // discarded

jshell> System.out.println("Hello")
Hello

jshell> System.out.println($4.getClass() == Class.forName("java.lang.Object"))
false

jshell> System.out.println($4.getClass() == java.lang.Object.class)
| Error:
| incomparable types: java.lang.Class<capture#2 of ? extends Object> and java.lang.Class<java.lang.Object>
| System.out.println($4.getClass() == java.lang.Object.class)
| ^-------------------------------------^

#2
$ jshell -v
| Welcome to JShell -- Version 21.0.2
| For an introduction type: /help intro

jshell> class Throwable {}
| created class Throwable

jshell> 0
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| 0
| ^

jshell> 0.0
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| 0.0
| ^

jshell> "string"
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| "string"
| ^

jshell> throw new Throwable()
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| throw new Throwable();
| ^--------------------^

jshell> throw new java.lang.Throwable()
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| throw new java.lang.Throwable();
| ^
| Error:
| unreported exception java.lang.Throwable; must be caught or declared to be thrown
| throw new java.lang.Throwable();
| ^------------------------------^

jshell> Objects.requireNonNull(null)
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| Objects.requireNonNull(null)
| ^

jshell> Objects.requireNonNull(new Object())
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| Objects.requireNonNull(new Object())
| ^

jshell> System.out.println("Hello")
| Error:
| incompatible types: Throwable cannot be converted to java.lang.Throwable
| System.out.println("Hello")
| ^

FREQUENCY : always