configure can't detect proper pthread flags

Hi,

when PostgreSQL is cross-compiled in the Buildroot with uClibc toolchain
it may not correctly detect compiler/linker flags for threading. [1]
The reason is that config/acx_pthread.m4:146 uses compiler and linker
stdout and stderr to make decision if acx_pthread_ok should be yes or no:

if test "`(eval $ac_link 2>&1 1>&5)`" = "" && test "`(eval
$ac_compile 2>&1 1>&5)`" = ""; then

and the toolchain emits the following warning at linking step:

libcrypto.so: warning: gethostbyname is obsolescent, use
getnameinfo() instead.

git log doesn't tell much why it is done that way. Does anybody know?
Can that test be rewritten as

if eval $ac_link 2>&1 1>&5 && eval $ac_compile 2>&1 1>&5 ; then

?

[1] http://comments.gmane.org/gmane.comp.lib.uclibc.buildroot/110204

--
Thanks.
-- Max