:type not works with -context

To Reproduce:
---

file `test1.go`:

```
package test

var x = 1
```

in shell:

```
gore -context test1.go
```

in gore:

```
gore> x
 1

gore> :t x
 type: cannot get type: x

gore> :t 1
 int
```

Expected:
---

`:t x` show type of `x` correctly.

Observed:
---

`x` is loaded to current environment but `:t x` doesn't works.
