Build error with recent default branch

[Torsten]

Since a couple of days, I get the following error when building octave
(default branch, last cset e6d3f4f9473c):

  CXX
libinterp/parse-tree/libinterp_parse_tree_libparse_tree_la-pt-eval.lo
libinterp/parse-tree/oct-parse.yy: In function ‘octave_value_list
Fassignin(octave::interpreter&, const octave_value_list&, int)’:
libinterp/parse-tree/oct-parse.yy:5651:27: error: ‘valid_identifier’ was
not declared in this scope
   if (valid_identifier (nm))
                           ^
libinterp/parse-tree/oct-parse.yy:5651:27: note: suggested alternative:
In file included from libinterp/parse-tree/oct-parse.yy:82:0:
../libinterp/corefcn/utils.h:44:15: note:   ‘octave::valid_identifier’
   extern OCTINTERP_API bool valid_identifier (const std::string& s);
               ^

This even happens after a "make distclean".

Is anyone else seeing this error?

Torsten