SPECjvm2008-MPEG performance regressions in 10-b31

Both:
   SPECjvm2008-MPEG
   SPECjvm98-Server.mpegaudio
have regressed with 10-b31.

The cases that reproduced through the triage process are:
• WXS / SPECjvm2008-MPEG-G1 approx -3.5%
• WXS / SPECjvm2008-MPEG-ParGC approx -2.5%
• WXS / SPECjvm98-Server.mpegaudio approx -3.5%
• MXS / SPECjvm98-Server.mpegaudio approx -1.7%

Regressions hold into subsequent releases, AND are behind the release baseline.

VMswap results indicate the cause to be in the JVM.

The MXS result may be noise, but included here for completeness.
Other platforms x64 show signs of being impacted, but statistical significance was reached (though they were close) and so they're not reported.


Copied from JDK-8194660

Both:
   SPECjvm2008-SOR.large-G1
   SPECjvm2008-SOR.large-ParGC
show regressions in 10-b31 on SPARC/Solaris.

• SPECjvm2008-SOR.large-G1 approx 0.5%
• SPECjvm2008-SOR.large-ParGC approx 0.9%