RFR 8194085: Obsolete the deprecated SafepointSynchronize flags and remove related code

[harold seigel]

Hi,

Please review this JDK-11 change to obsolete the 
SafepointSpinBeforeYield, DeferThrSuspendLoopCount, and 
DeferPollingPageLoopCount options and related code.  With this change, 
these options are still accepted on the command line but have no affect 
other than to generate these warning messages:

    Java HotSpot(TM) 64-Bit Server VM warning: Ignoring option
    SafepointSpinBeforeYield; support was removed in 11.0
    Java HotSpot(TM) 64-Bit Server VM warning: Ignoring option
    DeferThrSuspendLoopCount; support was removed in 11.0
    Java HotSpot(TM) 64-Bit Server VM warning: Ignoring option
    DeferPollingPageLoopCount; support was removed in 11.0

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8194085/webrev/index.html

JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8194085

The change was tested with Mach5 tiers 1 and 2 on all Mach5 platforms 
and tiers 3-5 in Linux-X64.

Thanks, Harold