This fixes Mantis bug #557.
compiler/module_qual.qualify_items.m:
When module qualifying checked type, inst and mode definitions,
- qualify the checked definition as appropriate to the module section
where the definition's body is, and
- do not discard any error messages generated by this process in favor of
the error messages (if any) generated by qualifying the source
definitions the checked definition was constructed from.
The source of the Mantis #557 bug was that in a type definition,
an argument type was (a) uniquely qualifiable in the interface section,
but (b) was ambiguous in the implementation section, due to an extra
module import being visible in the implementation section. The first
change above fixes this bug. The second change is there to ensure that
if we set the flag that says we found a non-uniquely-module-qualifiable
type, inst or mode name, the error message we generate when we do that
won't be discarded. The second change also means that such errors get
two error messages generated for them, but since we always sort
error_specs and any remove duplicates, this is not a problem.
tests/hard_coded/bug557.{m,exp}:
tests/hard_coded/bug557_helper.m:
The test case for this bug, with a comment explaining the bug.
tests/hard_coded/Mmakefile:
Enable the new test case.
