RFR: 8240370: Provide Intel JCC Erratum opt-out

[Erik Österlund]

Hi,

Today, the Intel JCC Erratum mitigation is automatically enabled when 
running on an affected machine.
While it is strongly recommended that customers run code in environments 
with the micro code updates
provided by Intel to mitigate the erratum, and hence are probably almost 
always better off with the
mitigation, there could be value in being able to opt out to analyze the 
performance characteristics
of an application, as a diagnostic option.

This patch adds a diagnostic option that allows you to opt out with: 
-XX:-IntelJccErratum

Webrev:
http://cr.openjdk.java.net/~eosterlund/8240370/webrev.00/

Bug:
https://bugs.openjdk.java.net/browse/JDK-8240370

Thanks,
/Erik