Bug: Global declaration of `set` fails

[kmr-srbh]

Declaring a set in the global scope fails. This however is not the case with a local scope like a function.

s: set[str] = {"a", "b", "c", "a"}
s.add("d")

(base) saurabh-kumar@Awadh:~/Projects/System/lpython$ ./src/bin/lpython ./examples/example.py
code generation error: Variable type not supported 6
 --> ./examples/example.py:1:1
  |
1 | s: set[str] = {"a", "b", "c", "a"}
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 

Note: Please report unclear or confusing messages as bugs at
https://github.com/lcompilers/lpython/issues.

As it turns out, the error message is not clear too.

[Shaikh-Ubaid]

In the code example shared in the issue description, you need not import set from the lpython module as set is predefined in cpython. You also need not import i32 as it is unused. So the example in the issue description can be simplified to:

s: set[str] = {"a", "b", "c", "a"}
s.add("d")