CRR (S): 7113012: G1: rename not-fully-young GCs as "mixed"

[Tony Printezis]

Hi all,

Could I have a couple of volunteers to look at this change?

http://cr.openjdk.java.net/~tonyp/7113012/webrev.0/

We decided that the terms "fully-young" and "partially-young" GCs were 
awkward so we are renaming them to "young" and "mixed". This change not 
only changes the external G1 output that uses these terms (i.e., GC log 
and GC ergonomic decision log) but also renames all the occurrences of 
those terms in the code itself (fields, methods, comments, etc.). 
Initially, I was not going to do the latter but it turned out that the 
changes were not too many. So it's good to make the code consistent with 
our current terminology.

These are the most common fields / methods that I renamed:

_full_young_gcs                  -> _gcs_are_young
full_young_gcs()                 -> gcs_are_young()
set_full_young_gcs()             -> set_gcs_are_young()
_should_revert_to_full_young_gcs -> _should_revert_to_young_gcs
_last_full_young_gc              -> _last_young_gc
_last_young_gc_full              -> _last_gc_was_young

The changeset also includes some very minor code cleanup (mainly 
introduction of curly brackets in if-else statements).

Tony