RFR (XXS): 8208672: Enable -Wreorder in make files

[Thomas Schatzl]

Hi,

  note: I have only been able to build Oracle platforms (x64-linux,
osx, sparc-solaris, win64) with this enabled. It would be nice to get
confirmation that other platforms will not break.

Thanks,
  Thomas

On Thu, 2018-08-02 at 11:14 +0200, Thomas Schatzl wrote:
> Hi all,
> 
>   there have been several suggestions to try to fix the Hotspot code
> to
> allow us to enable -Wreorder in the Hotspot sources.
> This should make problems due to use-before-initialization much more
> obvious.
> 
> This change enables -Wreorder for gcc and clang.
> 
> Of course it needs all previous RFRs sent to hotspot-dev to be
> checked
> in first to result in successful compilation of the code.
> 
> Also checked by looking at the generated spec.gmk file which seems to
> result in the flag in the I think "right" flag, but I am not very
> knowledgable in this area.
> 
> build-dev is CC'ed.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8208672
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8208672/webrev/
> Testing:
> hs-tier1-4,jdk-tier1-3
> 
> Thanks,
>   Thomas