RFR: 8134797: Remove explicit casts in CollectorPolicy hierarchy

[Thomas Schatzl]

Hi,

On Mon, 2015-08-31 at 21:04 -0400, Kim Barrett wrote:
> Please review this change to eliminate explicit casts within the
> CollectorPolicy hierarchy.  All of the casts being eliminated were
> C-style casts; there are no C++ style casts in this hierarchy.
> 
> For downcasts to GenCollectorPolicy* the policy was being obtained
> from a GenCollectedHeap, so we just use gen_policy instead of an
> unchecked downcast of collector_policy.
> 
> For the remaining downcast (to ConcurrentMarkSweepPolicy*) we now
> assert the corresponding is_xxx_policy and use as_xxx_policy to
> perform the conversion.
> 
> Changed the explicit upcasts to CollectorPolicy* to implict
> conversions.  For the problematic one, moved to a scope where
> G1CollectorPolicy is complete, so the now implicit conversion works.
> I'm kind of surprised that one didn't cause obvious problems.

 - please fix the indentation of method arguments in e.g.
genCollectedHeap.cpp:184 and genCollectedHeap.cpp:823 before pushing.

 - as Per already mentioned, g1CollectorPolicy.hpp is indirectly
included by g1CollectedHeap.o (via g1CollectedHeap.inline.hpp?), but
should be either made explicit, or the method kept in the cpp file. I
have no preference either way.

I do not need a re-review for these changes.

Thanks,
  Thomasa