RFR: 8277342: vmTestbase/nsk/stress/strace/strace004.java fails with SIGSEGV in InstanceKlass::jni_id_for

[Coleen Phillimore]

Use the version jni_id_for_impl() as jni_id_for() that takes out the JFieldIdCreation_lock before reading jni_ids in InstanceKlass.
Tested with mach5 tier1-3.

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Commit messages:
 - 8277342: vmTestbase/nsk/stress/strace/strace004.java fails with SIGSEGV in InstanceKlass::jni_id_for

Changes: https://git.openjdk.java.net/jdk/pull/6466/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6466&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277342
  Stats: 14 lines in 2 files changed: 0 ins; 12 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6466.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6466/head:pull/6466

PR: https://git.openjdk.java.net/jdk/pull/6466