RFR: 8277216: Examine InstanceKlass::_misc_flags for concurrency issues [v2]

[Coleen Phillimore]

> Recent bug in misc_flags showed that they are not set concurrently and could cause bugs.  Most of the misc_flags are set at classfile parsing time or at a safepoint and never reset.  This change adds an assert that the flag is set once.  See CR for more details.
> Tested with tier1-3.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Fix typo.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6851/files
  - new: https://git.openjdk.java.net/jdk/pull/6851/files/61c391aa..8f2406b7

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6851&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6851&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6851.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6851/head:pull/6851

PR: https://git.openjdk.java.net/jdk/pull/6851