RFR (S): 8245088: Always provide logs for G1 heap expansion calculations

[Thomas Schatzl]

Hi all,

   I would like the heap ergonomics code which determines by what amount 
to expand to always print internal state, not only on changes.

Since heap expansion is based on long term (and short term) application 
behavior, getting only information when something happened is too late 
to understand the results.

The gc+ergo+heap=debug log message has also been changed to include all 
interesting information; there is a new trace level message that tracks 
our low-pass filter.

CR:
https://bugs.openjdk.java.net/browse/JDK-8245088
Webrev:
http://cr.openjdk.java.net/~tschatzl/8245088/webrev/
Testing:
hs-tier1-5

Thanks,
   Thomas