Remove -w compile option in configure test.

Not all C compilers have a -w option.

configure

@@ -442,7 +442,7 @@ EOF
 if test $shared -eq 1; then
   echo Checking for shared library support... | tee -a configure.log
   # we must test in two steps (cc then ld), required at least on SunOS 4.x
-  if try $CC -w -c $SFLAGS $test.c &&
+  if try $CC -c $SFLAGS $test.c &&
      try $LDSHARED $SFLAGS -o $test$shared_ext $test.o; then
     echo Building shared library $SHAREDLIBV with $CC. | tee -a configure.log
   elif test -z "$old_cc" -a -z "$old_cflags"; then