RFR: JDK-8196951: jdk build fails with clang: error: no such file or directory: '@LIBZ_CFLAGS@'

[Tim Bell]

Erik:

> It seems my recent changes has caused yet another build failure. I'm
> puzzled over why this worked in our internal CI builds but fails in
> other situations. Some toolchains must simply be accepting @LIBZ_CFLAGS@
> on the command line. Anyway, the fix is to make sure the variables are
> always defined in configure:
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8196951
>
> Patch:
>
> diff -r 8cc67294ec56 make/autoconf/lib-bundled.m4
> --- a/make/autoconf/lib-bundled.m4
> +++ b/make/autoconf/lib-bundled.m4
> @@ -209,6 +209,8 @@
>       AC_MSG_ERROR([Invalid value for --with-zlib: ${with_zlib}, use
> 'system' or 'bundled'])
>     fi
>
> +  LIBZ_CFLAGS=""
> +  LIBZ_LIBS=""
>     if test "x$USE_EXTERNAL_LIBZ" = "xfalse"; then
>       LIBZ_CFLAGS="$LIBZ_CFLAGS
> -I$TOPDIR/src/java.base/share/native/libzip/zlib"
>     else

Looks good.

/Tim