PATCH: PR libjava/3207: Ignore _AC_ARG_VAR_PRECIOUS

[Paolo Bonzini]

>> As I said, I couldn't convince aclocal.m4 to do so (despite trying for
>> half an hour to remove autom4te.cache etc.).
> 
> You must have the correct version of autoconf (actually autom4te) in the
> path.

Right, I need to do

AUTOM4TE=autom4te-2.59 aclocal -I . -I .. -I ../config

This makes me wonder, though, if the correct solution wouldn't be to 
brittle (many people have Autoconf 2.59 installed manually, and let the 
distro package manager install the latest version as `autoconf' simply).

Paolo