Range types don't work with BackwardsIndex (and possibly others)

[PMunch]

I was trying to combine the two [] procedures in the deque module, one that takes Natural and one that takes BackwardsIndex. When I changed the type to Natural or BacwardsIndex and added a when switch in the body of the procedure it stopped accepting integers.

Example

proc test(x: Natural or BackwardsIndex): int =
  int(x)
  
echo test(^1) # This works
echo test(1)  # This doesn't

Current Output

Error: type mismatch: got <int literal(1)>
but expected one of: 
proc test(x: Natural or BackwardsIndex): int
  first type mismatch at position: 1
  required type for x: Natural or BackwardsIndex
  but expression '1' is of type: int literal(1)

expression: test(1)

Expected Output

1
1

[PMunch]

Changes the Natural to an int makes this example work fine.

[krux02]

probably related: #7265

[Clyybber]

Not really related I think. I think this is a sigmatch bug.