Convert the three derivation/cycle-pass compile checkers to located findings
so each error attaches to its declaring node instead of the schema root
(#169): an all-group referenced inside a sequence/choice/all locates on the
offending group reference (allGroupReferencePlacementFindings); a type
derived from itself locates on its complexType/simpleType
(derivationCycleFindings); and an element that is a member of its own
substitution group, or a model group or attribute group that references
itself, locates on its declaration (circularReferenceFindings).
The cycle checkers report a cycle by component name over a name-keyed graph,
so each now records the declaring node in a parallel nodeOf map built in the
same loop as the graph; a name that yields a finding always has a node, so a
mutual cycle underlines each member on its own declaration. Every predicate,
key ordering, and reason string is unchanged; only the location each finding
carries differs. 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, covering both substitution and group-reference
cycles.
Mihaela Mihaljevic
ee5c46929c