Fully unitialized constants are allowed by Titan
## Summary
According to Section 10 point d) of the TTCN-3 standard, "The right-hand side of the assignment that initializes a constant shall evaluate to an object that is at least partially initialized."
## Steps and/or TTCN-3 code to reproduce
```
type record myRecord{
integer field1,
charstring field2 optional,
integer field3
}
type record mymultirecord{
myRecord A,
myRecord B
}
type record of integer roi;
testcase partly_init_constants() runs on ct_empty{
const mymultirecord cr := {A := {field1 := 1, field2 := -, field3 := -}, B := -};
const mymultirecord ct := {A := -, B := -}; //should cause an error
const roi iro := {}; //should cause an error
setverdict(pass);
}
```
## What is the current bug behavior?
The test case passes.
## What is the expected correct behavior?
The indicated lines shall cause an error, as those constants are not even partially initialized (they have unbound fields).
## 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 @mmagyari
issue