Fixed compilation warnings in configuration C tests.

Based on a patch by Piotr Sikora.

auto/os/linux

diff --git a/auto/os/linux b/auto/os/linux
index 0b2173c..dba11a4 100644
--- a/auto/os/linux
+++ b/auto/os/linux
@@ -52,7 +52,7 @@
 ngx_feature_incs="#include <sys/epoll.h>"
 ngx_feature_path=
 ngx_feature_libs=
-ngx_feature_test="int efd = 0, fd = 1, n;
+ngx_feature_test="int efd = 0;
                   struct epoll_event ee;
                   ee.events = EPOLLIN|EPOLLOUT|EPOLLET;
                   ee.data.ptr = NULL;
@@ -142,7 +142,7 @@
 ngx_feature_path=
 ngx_feature_libs=-lcrypt
 ngx_feature_test="struct crypt_data  cd;
-                  crypt_r(NULL, NULL, &cd);"
+                  crypt_r(\"key\", \"salt\", &cd);"
 . auto/feature
 
 

auto/types/sizeof

diff --git a/auto/types/sizeof b/auto/types/sizeof
index e84a090..31411dd 100644
--- a/auto/types/sizeof
+++ b/auto/types/sizeof
@@ -20,12 +20,13 @@
 #include <sys/time.h>
 $NGX_INCLUDE_UNISTD_H
 #include <signal.h>
+#include <stdio.h>
 #include <sys/resource.h>
 $NGX_INCLUDE_INTTYPES_H
 $NGX_INCLUDE_AUTO_CONFIG_H
 
 int main() {
-    printf("%d", sizeof($ngx_type));
+    printf("%zu", sizeof($ngx_type));
     return 0;
 }
 

auto/types/typedef

diff --git a/auto/types/typedef b/auto/types/typedef
index f121e8f..6971900 100644
--- a/auto/types/typedef
+++ b/auto/types/typedef
@@ -28,7 +28,8 @@
 $NGX_INCLUDE_INTTYPES_H
 
 int main() {
-    $ngx_try i = 0;
+    $ngx_try i;
+    i = 0;
     return 0;
 }
 

auto/types/uintptr_t

diff --git a/auto/types/uintptr_t b/auto/types/uintptr_t
index 07f7e7d..2a00b49 100644
--- a/auto/types/uintptr_t
+++ b/auto/types/uintptr_t
@@ -4,8 +4,8 @@
 
 
 echo $ngx_n "checking for uintptr_t ...$ngx_c"
-echo >> $NGX_ERR
-echo "checking for uintptr_t" >> $NGX_ERR
+echo >> $NGX_AUTOCONF_ERR
+echo "checking for uintptr_t" >> $NGX_AUTOCONF_ERR
 
 found=no
 
@@ -15,13 +15,17 @@
 $NGX_INTTYPES_H
 
 int main() {
-    uintptr_t i = 0;
+    uintptr_t i;
+    i = 0;
     return 0;
 }
 
 END
 
-eval "$CC -o $NGX_AUTOTEST $NGX_AUTOTEST.c >> $NGX_ERR 2>&1"
+ngx_test="$CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
+          -o $NGX_AUTOTEST $NGX_AUTOTEST.c $NGX_LD_OPT"
+
+eval "$ngx_test >> $NGX_AUTOCONF_ERR 2>&1"
 
 if [ -x $NGX_AUTOTEST ]; then
     echo " uintptr_t found"

auto/unix

diff --git a/auto/unix b/auto/unix
index d786bb4..88b2cbe 100755
--- a/auto/unix
+++ b/auto/unix
@@ -237,7 +237,7 @@
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="struct statfs  fs;
-                  statfs(NULL, &fs);"
+                  statfs(\".\", &fs);"
 . auto/feature
 
 
@@ -249,7 +249,7 @@
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="struct statvfs  fs;
-                  statvfs(NULL, &fs);"
+                  statvfs(\".\", &fs);"
 . auto/feature
 
 
@@ -481,7 +481,7 @@
 ngx_feature="setproctitle()"
 ngx_feature_name="NGX_HAVE_SETPROCTITLE"
 ngx_feature_run=no
-ngx_feature_incs=
+ngx_feature_incs="#include <stdlib.h>"
 ngx_feature_path=
 ngx_feature_libs=$NGX_SETPROCTITLE_LIB
 ngx_feature_test="setproctitle(\"test\");"
@@ -585,7 +585,8 @@
 ngx_feature="memalign()"
 ngx_feature_name="NGX_HAVE_MEMALIGN"
 ngx_feature_run=no
-ngx_feature_incs="#include <stdlib.h>"
+ngx_feature_incs="#include <stdlib.h>
+                  #include <malloc.h>"
 ngx_feature_path=
 ngx_feature_libs=
 ngx_feature_test="void *p; p = memalign(4096, 4096)"