eval vs lvars scope

**Environment Information**
  
Provide at least:
* JRuby version (`jruby -v`): jruby 9.4.3.0 (3.1.4) 2023-06-07 3086960792 OpenJDK 64-Bit Server VM 25.372-b07 on 1.8.0_372-b07 +jit [aarch64-linux]

**Expected Behavior**

```ruby
a = nil
eval("1 => a")
a
#=> 1
```

**Actual Behavior**

```ruby
a = nil
eval("1 => a")
a
#=> nil
```

