Fix test for uintptr_t. Fixes #1568842.
Will backport.
diff --git a/configure b/configure
index ecbdf26..27541f1 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 51727 .
+# From configure.in Revision: 51971 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.59 for python 2.6.
 #
@@ -10073,20 +10073,26 @@
 
 fi
 
-echo "$as_me:$LINENO: checking for uintptr_t support" >&5
-echo $ECHO_N "checking for uintptr_t support... $ECHO_C" >&6
-have_uintptr_t=no
-cat >conftest.$ac_ext <<_ACEOF
+echo "$as_me:$LINENO: checking for uintptr_t" >&5
+echo $ECHO_N "checking for uintptr_t... $ECHO_C" >&6
+if test "${ac_cv_type_uintptr_t+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
+#include <stdint.h>
 
 int
 main ()
 {
-uintptr_t x; x = (uintptr_t)0;
+if ((uintptr_t *) 0)
+  return 0;
+if (sizeof (uintptr_t))
+  return 0;
   ;
   return 0;
 }
@@ -10113,23 +10119,23 @@
   ac_status=$?
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }; }; then
-
-
-cat >>confdefs.h <<\_ACEOF
-#define HAVE_UINTPTR_T 1
-_ACEOF
-
-  have_uintptr_t=yes
-
+  ac_cv_type_uintptr_t=yes
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5
 
+ac_cv_type_uintptr_t=no
 fi
 rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
-echo "$as_me:$LINENO: result: $have_uintptr_t" >&5
-echo "${ECHO_T}$have_uintptr_t" >&6
-if test "$have_uintptr_t" = yes ; then
+fi
+echo "$as_me:$LINENO: result: $ac_cv_type_uintptr_t" >&5
+echo "${ECHO_T}$ac_cv_type_uintptr_t" >&6
+if test $ac_cv_type_uintptr_t = yes; then
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_UINTPTR_T 1
+_ACEOF
+
 echo "$as_me:$LINENO: checking for uintptr_t" >&5
 echo $ECHO_N "checking for uintptr_t... $ECHO_C" >&6
 if test "${ac_cv_type_uintptr_t+set}" = set; then
@@ -10546,6 +10552,8 @@
 
 fi
 
+
+
 # Hmph. AC_CHECK_SIZEOF() doesn't include <sys/types.h>.
 echo "$as_me:$LINENO: checking size of off_t" >&5
 echo $ECHO_N "checking size of off_t... $ECHO_C" >&6