On AIX, the resolver functions are in libc, so trying libresolv
will cause the checks to fail. The behaviour should be instead
like AC_SEARCH_LIBS.
This hardcodes a check not to use libresolv on AIX. Better than
nothing, but it may not compensate for other systems without a
libresolv.
GitHub's file finder filters out "build/" directories, among others, which can make it difficult to quickly access these files. Also, the "build/" directory doesn't provide much value here, since it only contains "autotools/".
