[11] RFR: 8145665: Make UseSSE an x86 specific option and cleanup its usage in shared code

[Rahul Raghavan]

Hi,

JBS - https://bugs.openjdk.java.net/browse/JDK-8145665

Request help to review, confirm if 8145665 requirement can be achieved 
with following proposed changes.

webrev.00 - http://cr.openjdk.java.net/~rraghavan/8145665/webrev.00/


-- UseSSE option moved from globals.hpp to globals_x86.hpp,
usages in shared code guarded for x86 wherever missing.

-- Also found two tests required to use -XX:UseSSE option.
(Test6579789.java, Test6855215.java)
(confirmed the UseSSE requirement for these tests from the old related 
bugs notes.)
So added @requires for the tests to prevent from running and failing in 
Sparc after 8145665 changes.

-- No issues with local builds, hs-tier1,hs-tier2 testing, 
pre-integeration testing in progress

-- I will also work for other related task - JDK-8038595
'Using platform specific flags may cause VM crash'


Thanks,
Rahul