PR# 19890 Inconsistent results of {detachable separate CHARACTER_REF}.out

Given an entity a: A, where A is a formal generic parameter, the feature a.out may produce inconsistent results when the actual generic is of type {detachable separate CHARACTER_REF}.

- Open and compile the st_implementation_bugs target of (attached) .\main\st_implementation\st_implementation.ecf project.
- Run the Workbench system (F5).
- Eventually, one gets the CHECK_VIOLATION below
SEPARATE_OUT_BUG_DSCR
                    reproduce_separate_out_bug @5
                                           s1.hash_code = s2.hash_code
- Within the Objects tool one can see that either `s1' or `'s2' equals "%U", although `a' (the sole source of the values of s1 and s2) is not a reference to a null character.

Attachments for problem report #19890