RFR(S): 8166461: Deprecate UseAutoGCSelectPolicy

[sangheon]

Hi all,

Can I have some reviews for this change to deprecate 
UseAutoGCSelectPolicy command-line option?

The intent of UseAutoGCSelectPolicy option is to provide a way to 
automatically select GC based on target pause time. This option is 
introduced with AutoGCSelectPauseMillis and if MaxGCPauseMillis is 
smaller than or equal to AutoGCSelectPauseMillis(and if GC is not 
specified), low pause collector will be selected. I think it is enough 
to accomplish auto-GC-selection without UseAutoGCSelectPolicy.

This patch only includes adding the deprecation message for 
UseAutoGCSelectPolicy option.

CR: https://bugs.openjdk.java.net/browse/JDK-8166461
Webrev: http://cr.openjdk.java.net/~sangheki/8166461/webrev.0
Testing: JPRT

Thanks,
Sangheon