RFR: 8202579: Revisit VM_Version and VM_Version_ext for overlap and consolidation

[Coleen Phillimore]

This change makes VM_Version_Ext part of VM_Version (the platform dependent part) and moves some duplicated code.  x86 had the most code in VM_Version_Ext, so the most code moved there. There might be some unneeded functions but I didn't want to remove them with this change.

Tier1 (tier2-4 testing in progress) on linux and windows for x86, aarch64, Oracle platforms and tested builds on:
linux-aarch64-debug,linux-x86-open,linux-s390x-open,linux-arm32-debug,linux-ppc64le-debug
and
linux-x64-zero,linux-x64-zero-debug,linux-x86-zero,linux-x86-zero-debug

Ran JFR tests manually (it uses os_perf* CPUInformationInterface code).

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Commit messages:
 - Refactor cpu_name, etc into abstract_vm_version.
 - 8202579: Revisit VM_Version and VM_Version_ext for overlap and consolidation

Changes: https://git.openjdk.java.net/jdk/pull/6820/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6820&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8202579
  Stats: 2972 lines in 33 files changed: 1105 ins; 1830 del; 37 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6820.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6820/head:pull/6820

PR: https://git.openjdk.java.net/jdk/pull/6820