RFR 8215731: Move forward class definitions out of globalDefinitions.hpp

[David Holmes]

Hi Coleen,

Seems fine.

Thanks,
David

On 4/01/2019 1:20 pm, coleen.phillimore at oracle.com wrote:
> Summary: redistribute the forward declarations to the header files that 
> need them.
> 
> Tested with mach5 tier1 and 2, also tested aarch64 with cross compiler 
> and zero.
> 
> open webrev at http://cr.openjdk.java.net/~coleenp/8215731.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8215731
> 
> Thanks,
> Coleen
>