[m-rev.] for post-commit review: fix mantis bug 545

[Julien Fischer]

On Wed, 9 Feb 2022, Zoltan Somogyi wrote:

> Fix quoting of attributes in type defns.
> 
> This fixes Mantis bug #545.
> 
> compiler/parse_tree_out.m:
>     Put brackets around functor names in "where direct_arg is" attributes.
> 
> compiler/mercury_to_mercury.m:
>     Provide a function for doing that.
> 
> tests/valid_seq/xml_event_read.m:
> tests/valid_seq/xml_event_read_helper.m:
>     A slightly modified version of the Mantis test case.
> 
> tests/valid_seq/Mmakefile:
> tests/valid_seq/Mercury.options:
>     Enable the new test case, and compile it with intermodule optimization
>     to (try to) tickle the bug.

That's fine.

Julien.