Extends the compile-time attribute-model check. A component's name must be a
valid NCName, the reference attributes type/base/ref/itemType/refer/
substitutionGroup must be lexical QNames, and memberTypes a list of QNames.
These were unchecked, so name="", name="123", name="a:b", or type=":_" left the
schema wrongly accepted.
Only the lexical form is checked (a QName's prefix is resolved elsewhere), so a
valid reference is never rejected; each of these attribute names has one type
throughout XSD, so checking by local name is safe.
XSTS: invalid schemas accepted 1190 to 1129 (-61); valid schemas rejected held
at 72 (no over-rejection); instance buckets unchanged.
Mihaela Mihaljevic
ca8fd27877