RFR: 8178889: Move creation of AbstractChronology comparators to call sites

[Claes Redestad]

Hi,

in AbstractChronology we define a number of comparators which could be 
moved to their
respective call site and thus be lazily initialized when needed with no 
performance
penalty.

Bug: https://bugs.openjdk.java.net/browse/JDK-8178889
Webrev: http://cr.openjdk.java.net/~redestad/8178889/jdk.01/

Testing/analysis:
- naive micro to show this doesn't cause a regression in steady 
state[1], for those in
doubt
- reduces executed bytecode by ~127K and drops 5 generated classes from 
startup of
applications that depend on AbstractChronology but don't use any of 
these comparators
- pass all java/time tests

Thanks!

/Claes

[1]
package org.openjdk;
import org.openjdk.jmh.annotations.Benchmark;
import java.time.chrono.*;
import java.lang.reflect.*;

public class ChronoComparatorBench {

     public static Method timeLineOrder;

     static {
         try {
             timeLineOrder = 
ChronoLocalDate.class.getDeclaredMethod("timeLineOrder");
         } catch (Exception e) {
             throw new RuntimeException(e);
         }
     }

     @Benchmark
     public Object getComparator() throws Exception {
         return timeLineOrder.invoke(null);
     }
}

-f 1 -tu us -bm avgt

Benchmark                            Mode  Cnt  Score   Error Units
ChronoComparatorBench.getComparator  avgt   20 5.979 ± 0.067  ns/op  # 
before
ChronoComparatorBench.getComparator  avgt   20 5.975 ± 0.054  ns/op  # after