Add address checking in clang to -w option of configure.
diff --git a/configure b/configure
index e974d1f..f412795 100755
--- a/configure
+++ b/configure
@@ -194,9 +194,9 @@
   fi
   if test "$warn" -eq 1; then
     if test "$zconst" -eq 1; then
-      CFLAGS="${CFLAGS} -Wall -Wextra -Wcast-qual -pedantic -DZLIB_CONST"
+      CFLAGS="${CFLAGS} -Wall -Wextra -Wcast-qual -pedantic -DZLIB_CONST -fsanitize=address"
     else
-      CFLAGS="${CFLAGS} -Wall -Wextra -pedantic"
+      CFLAGS="${CFLAGS} -Wall -Wextra -pedantic -fsanitize=address"
     fi
   fi
   if test $debug -eq 1; then