RFR(XS): 8078243: Fix include of stack.inline.hpp in taskqueue.hpp.

[Thomas Schatzl]

Hi Goetz,

On Tue, 2015-04-21 at 08:20 +0000, Lindenmaier, Goetz wrote:
> Hi,
>  
> another include that’s missing.  This time it breaks aix only, would
> not have been 
> detected by non-pch build J
> taskqueue.hpp calls Stack::push(), thus it must include
> stack.inline.hpp.

.inline.hpp files should not be included by .hpp files because this
often causes lots of additional files to be included, and is prone to
creating include dependency cycles.

I think the only option here is to move the inline methods into their
own taskqueue.inline.hpp file that is included in the appropriate
places.

Thanks,
  Thomas