[m-rev.] for review: don't put duplicate instance decls into .int0 files

[Julien Fischer]

On Fri, 30 Jun 2023, Zoltan Somogyi wrote:

> Don't generate duplicate instance declarations.
> 
> We used to include in the .int0 file the abstract form of all the instance
> declarations in both the interface and the implementation sections.
> When an instance is declared (in an already-abstract form) in the interface
> section and defined in the implementation section, this resulted in the
> abstract interface declaration being included in the .int0 file twice,
> once in the interface section, and once in the implementation section.
> 
> compiler/comp_unit_interface.m:
>     Fix this by include an abstract instance declaration in the implementation

s/include/including/

Julien.