Basic group incremental parse erorr in 0.9.4. Works in 0.9.1 and prior

[rooooooooob]

Repro code (on 0.9.4):

let cddl = cddl::parser::cddl_from_str(
    r#"basic = (d: #6.23(uint), e: bytes)
    outer = [a: uint, b: basic, c: "some text"]"#,
    true
)?;

Error:

error: parser errors
  ┌─ input:2:22
  │
2 │ outer = [a: uint, b: basic, c: "some text"]
  │                      ^^^^^ missing definition for rule basic

This parses fine on 0.9.1 and various previous versions (we've had this in a test case for a long time in cddl-codegen).

[rooooooooob]

Note: it seems to be able to be used in other contexts, for example:

group_choice = [ foo // 0, x: uint // basic ]

does not complain about basic having a missing definition on 0.9.4