RFR (S): 8238160: Uniformize Parallel GC task queue variable names

[Kim Barrett]

> On Jan 30, 2020, at 6:08 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi all,
> 
>  can I have reviews for this small change that moves some global typedefs used only by Parallel GC from taskqueue.hpp to parallel gc files, and further makes naming of instances of these more uniform?
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8238160
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8238160/webrev/
> Testing:
> local compilation
> 
> Thanks,
>  Thomas

The various "guarantee" checks that operator new didn't return NULL
are a waste of time and space; CHeapObj's operator new exits rather
than returning NULL. They are culterally compatible with other nearby
code though; cleanup later?

Looks good as is.