RFR: 8256536: Newer AMD 19h (EPYC) Processor family defaults

[Rohit Arul Raj]

This patch sets the following flags as defaults for newer AMD 19h (EPYC) processors.
      bool UseFPUForSpilling               = true   
      bool UseUnalignedLoadStores    = true   
      bool UseXMMForArrayCopy        = true   
      bool UseXMMForObjInit             = true   
      bool UseFastStosb                       = false  
      bool AlignVector                          = false  

Additional testing: make run-test TEST="tier1 tier2" JTREG="JOBS=128" CONF=linux-x86_64-server-fastdebug

Please review this change.

Thanks,
Rohit

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Commit messages:
 - 8256536: Newer AMD 19h (EPYC) Processor family defaults

Changes: https://git.openjdk.java.net/jdk/pull/1288/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1288&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256536
  Stats: 12 lines in 1 file changed: 9 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1288.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1288/head:pull/1288

PR: https://git.openjdk.java.net/jdk/pull/1288