Ticket History #8597: acx_pthread.m4 needs to be updated

When trying to compile the conftest.c program produced by the current
src/config/ac-archive/acx_pthread.m4 using the most current Solaris
Studio compiler produces this error:

configure:5958: checking for the pthreads library -lpthread
configure:5991: /ws/on12-tools/SUNWspro/developerstudio12.5/bin/cc -o
conftest -m32 -xO4 -xchip=pentium -xregs=no%frameptr -mt -D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITS=64 -KPIC -DPIC -errtags=yes -errwarn=%all
-errwarn=no%E_STATEMENT_NOT_REACHED -errwarn=no%E_NO_IMPLICIT_DECL_ALLOWED
-errwarn=no%E_EMPTY_TRANSLATION_UNIT -errwarn=no%E_EMPTY_INITIALIZER
-errwarn=no%E_EMPTY_DECLARATION -errwarn=no%E_ENUM_VAL_OVERFLOWS_INT_MAX
-errwarn=no%E_DEPRECATED_ATT -errwarn=no%E_INIT_SIGN_EXTEND
-errwarn=no%E_ASSIGNMENT_TYPE_MISMATCH -m32 -I/usr/include/openldap -lc
-zdefs conftest.c -lpthread -lresolv >&5
"conftest.c", line 43: Error : Likely uninitialized read (variable th): main
(SEC_UNINITIALIZED_MEM_READ)

This issue is solved with the latest version of acx_pthread.m4 See:

http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_pthread.m4
http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_pthread.m4

Specifically this commit fixed the problem:
http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=commit;h=0728dab771b2a4da8032d5f0ade8870add680b39

It would be nice if krb5 src included the latest version of
ax_pthread.m4.