additional reworking of error handling in the parser (bug #46877) * oct-parse.in.yy (ABORT_PARSE): Delete. Replace all uses with YYABORT. Ensure that all uses of octave_base_parser::bison_error are followed by YYABORT. (octave_base_parser::make_for_command): Always delete unused parse tree elements if an error is detected. octave_base_parser::make_index_expression): Likewise. (octave_base_parser::parse_error_msg): New data member. (octave_base_parser::bison_error): Store error message for later use instead of calling parse_error. (octave_parser::run, octave_push_parser::run): Check return status of Bison-generated parser and call parse_error here with stored message. Handle exceptions generated while parsing.

gnulib-hg = gnulib-hg