Importing std/enumerate breaks arraymancer
This works:

```nim
import arraymancer
let foo = @[1, 2, 3].to_tensor
echo foo
```

This doesn't:

```nim
import arraymancer
import std/enumerate

let foo = @[1, 2, 3].to_tensor
echo foo
```

```
Error: type mismatch: got <Tensor[system.int]>
but expected one of:
proc echo(x: varargs[typed, `$`])
  first type mismatch at position: 1
  required type for x: varargs[typed]
  but expression 'foo' is of type: Tensor[system.int]

expression: echo foo
```

Version info:

```
nim --version
Nim Compiler Version 1.6.0 [Linux: amd64]
Compiled at 2021-10-19
Copyright (c) 2006-2021 by Andreas Rumpf

git hash: 727c6378d2464090564dbcd9bc8b9ac648467e38
active boot switches: -d:release
```