inner type unreachable with 2D record of integer

Summary

After creating a 2-dimensional integer array type, the innermost type is unreachable with the [-] notation

Steps and/or TTCN-3 code to reproduce

Use this code in a module:

type record length (10) of record length (10) of integer Matrix;
type record of integer ROI;

const ROI[-] c := 1;
const Matrix[-][-] c_MyInnermostInt := 1;

What is the current bug behavior?

ROI[-] resolves to integer, but Matrix[-][-] results in an error

What is the expected correct behavior?

Matrix[-][-] should resolve to integer.

Relevant logs and/or screenshots

Possible fixes

Titan version

8.1.0

Platform details (OS type and version)

Microsoft Windows 10 Enterprise 10.0.19042

/cc @aknappqwt