RFR: Fix ordering of macros in vmStructs_gc.hpp and globals_gc.hpp

[Aleksey Shipilev]

On 12/3/18 2:05 PM, Roman Kennke wrote:
> Following up Per's review, fix orderings in vmStructs_gc.hpp and
> globals_gc.hpp.
> 
> http://cr.openjdk.java.net/~rkennke/fix-macro-order/webrev.00/

Looks good.

-Aleksey