mengsuenyan fea822792f
Fixed the panic when type a statement similar to let f = 'f' $ in the nushell (#9851)
- this PR should close #9596 
- fixes #9596 
- this PR should close #9826 
- fixes #9826 

fixed the following bugs:
```nu
# type following statements in the nushell
let f = 'f' $;
mut f = 'f' $;
const f = 'f' $;

# then remove variable f, it will panics
let = 'f' $;
mut  = 'f' $;
const = 'f' $;
```
2023-08-02 04:21:40 +12:00
..
2023-07-03 17:45:10 +12:00
2023-07-16 12:25:12 +12:00