RFR: 8291360: Create entry points to expose low-level class file information

[Harold Seigel]

Please review this change to fix JDK-8291360.  This fix adds entry points getClassFileVersion() and getClassAccessFlagsRaw() to class java.lang.Class.  The new entry points return the current class's class file version and its raw access flags.

The fix was tested by running Mach5 tiers 1-2 on Linux, Mac OS, and Windows, and Mach5 tiers 1-3 on Linux x64.  Additionally, the JCK lang, vm, and api tests and new regression tests were run locally on Linux x64.

Thanks, Harold

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Commit messages:
 - 8291360: Create entry points to expose low-level class file information

Changes: https://git.openjdk.org/jdk/pull/9688/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9688&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8291360
  Stats: 704 lines in 9 files changed: 703 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/9688.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9688/head:pull/9688

PR: https://git.openjdk.org/jdk/pull/9688