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

[David Holmes]

Hi Thomas,

On 2/08/2018 7:14 PM, 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.

For Windows (VS2017+) see:

https://docs.microsoft.com/en-us/cpp/error-messages/compiler-warnings/c5038

Otherwise change seems okay.

Thanks,
David

> 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
>