RFR: 8134626 - Misc cleanups after generation array removal

[Jesper Wilhelmsson]

Hi,

Please review this rather large cleanup. While working with the generation array 
removal I did a bunch of unrelated cleanups in the code I passed by. I split 
this out into a separate patch to keep the other changes clean.

This change is split into three webrevs to make it easier to review. I intend to 
push all three as one change.

Bug: https://bugs.openjdk.java.net/browse/JDK-8134626


Increment 1: Renaming
http://cr.openjdk.java.net/~jwilhelm/8134626/webrev.00/inc1-renaming/

Changes the variable name gen to young_gen or old_gen depending on what the 
variable will contain. The few cases where the name gen is untouched are places 
where the variable actually can contain either generation.


Increment 2: Comments and indentation
http://cr.openjdk.java.net/~jwilhelm/8134626/webrev.00/inc2-comments_and_indentation/

* Fixes up alignment in lots of places.
* Inserts and removes empty lines where needed.
* Cleans up comments where we previously talked about older and younger 
generations. Fixes a few typos and clarifies some comments with respect to 
young/old generations and collections.
* Added spaces around some operators.


Increment 3: Code changes
http://cr.openjdk.java.net/~jwilhelm/8134626/webrev.00/inc3-code_changes/

* Merged strings that was split on several lines for no good reason.
* Added braces for if statements and for loops.
* Removed dead code.
* Moved variable initialization to initializer list in CollectedHeap constructor.
* Updated flag descriptions "youngest" -> "young".

Thanks,
/Jesper