Convert the three attribute-pass compile checkers to located findings so
each error attaches to its declaring node instead of the schema root (#169):
an attribute declaration in the XSI namespace locates on the attribute
(xsiNamespaceAttributeFindings); a duplicate attribute use or a second
ID-typed attribute locates on its declaring complexType or attributeGroup,
and an attribute reference contradicting a global fixed value locates on the
reference (attributeUseFindings); and a complex-type restriction that
relaxes a base attribute use or widens the attribute wildcard locates on the
restriction (attributeRestrictionFindings).
Each predicate, traversal order, and reason string is unchanged; only the
location each finding carries differs. The set-level uniqueness/single-ID
findings reuse the existing attributeSetErrors helper, mapping each onto its
declaring container node. An attribute restriction violation has no source
node of its own (the attribute use is a resolved model value), so it locates
on the restriction performing the illegal narrowing. The three checkers had
exactly one caller each, so each is renamed in place and the .unlocated wrap
dropped. Adds a located-diagnostics test per checker family.
Mihaela Mihaljevic
49fe824601