popt: solve the glob_pattern_p() problem

popt: solve the glob_pattern_p() problem

The current popt build system tests the existence of <glob.h>, and
then assumes that if __GLIBC__ is defined, then glob_pattern_p() must
be available. Unfortunately, that's not true with uClibc: <glob.h> may
be installed, but not necessarily the GNU glob extensions... and
uClibc defines __GLIBC__. This is causing build issues with certain
uClibc toolchains that do not have GNU glob extensions enabled.

To fix this, we introduce a patch called popt-03-glob-detection.patch
which adds a new AC_CHECK_FUNCS() test for glob_pattern_p() and uses
the result to know if this function is available, instead of testing
__GLIBC__.

In order for this patch to work, the popt package must be
autoreconfigured, so another patch, popt-02-fix-autoreconf.patch, is
needed to make the package autoreconfigure properly. And also
POPT_AUTORECONF = YES is added to popt.mk.

Finally, this change avoids the need for the Blackfin toolchain
specific testing, which we forgot to update when introducing the
2014R1 version of the Blackfin toolchain. With this new solution,
there will be no need to update the popt.mk file when new Blackfin
toolchains are added.

Fixes:

  http://autobuild.buildroot.org/results/e09/e09e24fec240382a3197fef3e98eb9a22f76420a/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Yuvaraj Patil <yuvaraj.patil@wipro.com>
Cc: Sonic Zhang <sonic.zhang@analog.com>