RFR: JDK-8175795 configure should verify that system zlib contains needed functionality

[Magnus Ihse Bursie]

I retract this review for now. The issue turned out to be not so simple 
as this. We *are* able to build with older versions of zlib. The 
dependency for inflateValidate arises from the bundled libpng; a system 
libpng does not necessary have that issue.

/Magnus

On 2017-12-04 11:57, Magnus Ihse Bursie wrote:
> If we're using the system zlib instead of the bundled zlib, we should 
> verify that it includes all relevant functions. We now rely on the 
> inflateValidate() function, which was introduced in zlib 1.2.9 which 
> is very recent. This patch adds a test to the system zlib to verify 
> this and to fail fast in case it's too old.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8175795
> WebRev: 
> http://cr.openjdk.java.net/~ihse/JDK-8175795-check-for-system-zlib-functionality/webrev.01
>
> /Magnus
>