eliminate unnecessary tree_funcall class The tree_funcall class was only used to handled generated calls to internal functions used by classdef superclass reference and metaclass query operations. This change replaces those function calls by something more direct. * pt-classdef.h, pt-classdef.cc (tree_superclass_ref, tree_metaclass_query): New classes. * pt-walk.h (tree_walker::visit_tree_funcall): Delete. Update all derived classes. (tree_walker::visit_superclass_ref, tree_walker::visit_metaclass_query): New virtual functions. * pt-pr-code.h, pt-pr-code.cc (tree_print_code::visit (tree_print_code::visit_superclass_ref, tree_print_code::visit_metaclass_query): Correctly print these parse tree elements. * oct-parse.yy (superclass_identifier, meta_identifier): Use new tree_superclass_ref tree_metaclass_query classes instead of tree_funcall to represent these language elements. * lex.ll (base_lexer::handle_superclass_identifier): Attempt to make intent of code clearer. Save line and column info in token. * pt-eval.h, pt-eval.cc (tree_evaluator::visit_funcall): Delete. (tree_evaluator::visit_superclass_ref, tree_evaluator::visit_metaclass_query): New functions. Handle superclass reference and metaclass query operations more directly. * ov-classdef.h, ov-classdef.cc (F__superclass_reference__, F__meta_class_query__): Delete. (class octave_classdef_superclass_ref): Work directly with method or object and class names as strings instead of octave_value objects. (octave_classdef::superclass_ref, octave_classdef::metaclass_query): New static functions. * token.h, token.cc: Attempt to use clearer names for superclass reference tokens. * pt-funcall.h, pt-funcall.cc: Delete. * libinterp/parse-tree/module.mk: Update. * pt-all.h: Update.