Most of modifier diagnostic is expressed by REDUNDANT_MODIFIER, INCOMPATIBLE_MODIFIERS, REPEATED_MODIFIER, WRONG_MODIFIER_TARGET, WRONG_MODIFIER_PARENT.
A set of modifier diagnostics is not in use now (but not deleted yet).
Now with nested classes the expression "A.something" makes sense even when A
doesn't have a class object ("something" could be a nested class)
Also "A" expression now gets a NamespaceType with the scope of all static
nested classes of A
#KT-1174 In Progress
Mikhail Glukhikh