RFR (S) 8245720: Shenandoah: improve configuration logging

[Aleksey Shipilev]

RFE:
  https://bugs.openjdk.java.net/browse/JDK-8245720

As the follow up of JDK-8244817 for Shenandoah GC, it makes sense to enable Shenandoah to print
similar info. Example output:

[0.006s][info][gc] Using Shenandoah
[0.006s][info][gc] Heuristics ergonomically sets -XX:+ExplicitGCInvokesConcurrent
[0.006s][info][gc] Heuristics ergonomically sets -XX:+ShenandoahImplicitGCInvokesConcurrent
[0.360s][info][gc,init] Version: 15-internal+0-adhoc.shade.jdk-jdk (fastdebug)
[0.360s][info][gc,init] CPUs: 16 total, 16 available
[0.360s][info][gc,init] Memory: 125G
[0.360s][info][gc,init] Large Page Support: Disabled
[0.360s][info][gc,init] NUMA Support: Disabled
[0.360s][info][gc,init] Compressed Oops: Enabled (Zero based)
[0.360s][info][gc,init] Heap Min Capacity: 1G
[0.360s][info][gc,init] Heap Initial Capacity: 1G
[0.360s][info][gc,init] Heap Max Capacity: 10G
[0.360s][info][gc,init] Pre-touch: Disabled
[0.360s][info][gc,init] Mode: Snapshot-At-The-Beginning (SATB)
[0.360s][info][gc,init] Heuristics: Adaptive
[0.360s][info][gc,init] Heap Region Count: 2560
[0.360s][info][gc,init] Heap Region Size: 4M
[0.360s][info][gc,init] TLAB Size Max: 4M
[0.360s][info][gc,init] Humongous Object Threshold: 4M
[0.360s][info][gc,init] Reference Processing: Parallel discovery, Parallel processing
[0.360s][info][gc,init] Parallel Workers: 8
[0.360s][info][gc,init] Concurrent Workers: 4
Ready

I am thinking to just inline the upstream superclass InitLogger into ShenandoahInitLogger when
backporting this to 11u and 8u.

Webrev:
  https://cr.openjdk.java.net/~shade/8245720/webrev.01/

Testing: hotspot_gc_shenandoah

-- 
Thanks,
-Aleksey