While attempting to regenerate and modernise the autotools scripts in libjava, both autoconf and autoreconf have resulted in a broken configure script filled with errors such as "as_fn_executable_p: command not found". To my knowledge this is because they are lacking the line (outside of the config.status section) "as_executable_p=as_fn_executable_p", as can be seen on line 547 of gotools/configure. But I cannot see anything in gotools/ configure.ac that would seem to generate this line, so I presume it is a different way of generating configure.
