Before this it would raise if zjit wasn't enabled
and raise a different exception if zjit was but extended stats were
not (_some_ stats are available).

Co-authored-by: Randy Stauner <randy@r4s6.net>

Fix up ruby/ruby#15414, 29c29c2b7e972359ab83038c5dc27a7e53ae65c7

The `--zjit-stats-quiet` and `--zjit-stats=quiet` options differ.
The latter option, `=quiet`, does print stats to the file "quiet", but
does not suppress output like yjit option `--yjit-stats=quiet`.

Fix up ruby/ruby#15414, 29c29c2b7e972359ab83038c5dc27a7e53ae65c7

Avoid garbage reads from locals in eval.
Before the fix the test fails with

    <"[\"x\", \"x\", \"x\", \"x\"]"> expected but was
    <"[\"x\", \"x\", \"x\", \"x286326928\"]">.

With the following code:

```ruby
object = []
object.singleton_class
object.freeze
object.instance_variable_set(:@a, 42)
```

The previous error message was:

```
can't modify frozen #<Class:#<Array:0x00000631d1308f78>>: []
```

With this change, the error message is:

```
can't modify frozen Array: []
```

Since we show the inspect value of the affected object, I think
including the singleton class instead of the actual class if it
exists makes the error message harder to understand.