improve previous fix for clear in nested scopes (bug #53027) * symrec.h (symbol_record::unbind_fwd_rep): New arg, recurse. (symbol_record::symbol_record_rep::unbind_fwd_rep): New arg, recurse. If TRUE, recurse to find ultimate rep. * symscope.cc (symbol_scope_rep::unbind_script_symbols): Don't recurse when unbinding script symbols. * symscope.h (symbol_record_rep::clear_varaible, symbol_record_rep::clear_variable_pattern, symbol_record_rep::clear_variable_regexp): If scope is nested, check parent for symbols. * test/bug-53027/globals53027.m, test/bug-53027/gtest53027.m: New test scripts. * test/bug-53027/ntest53027c.m: New test function. * test/bug-53027/ntest53027b.m: Fix typo. * test/bug-53027/bug-53027.tst: Update. * test/bug-53027/module.mk: Update.

function [m_exist, n_exist] = ntest53027b ()
  global x
  x = 3;
  n_exist = nest ();
  m_exist = exist ("x", 'var');
  function n_exist = nest ()
    ## The clear statement should operate on the variable in the
    ## parent scope even though there is no explicit varabiable
    ## reference in the code (the clear function just sees a string
    ## containing the name of the variable and the parser (correctly)
    ## does not treat this as a special case.
    clear x
    n_exist = exist ("x", "var");
  endfunction
endfunction