Error when generating PER descriptor containing reference to a constant in another module
## Summary
ASN.1 type constraints can contain references to constants, which are generated into the C++ code if these constraints are relevant to PER. If the referenced constant is defined in another ASN.1 module, then the compiler crashes with a fatal error.
## Steps and/or TTCN-3 code to reproduce
Imported module:
`objid-val OBJECT IDENTIFIER ::= { itu-t(0) recommendation(0) a(1) b(3) }`
Importing module:
`CharStr ::= CHARACTER STRING ( WITH COMPONENTS { identification ( syntaxes: { abstract objid-val, transfer objid-val } ) } )`
## What is the current bug behavior?
Compiler crashes with a fatal error
## What is the expected correct behavior?
Successful code generation
## Relevant logs and/or screenshots
-
## Possible fixes
Implement Ref_defd::generate_code_const_ref()
## Titan version
10.0.0
## Platform details (OS type and version)
Ubuntu 22.04
/cc @aknappqwt @mmagyari
issue