[lworld] Integrated: [lworld] temporary fix to serviceability HiddenClassSigTest test until JDK-8247491 fixes it properly

[Mandy Chung]

A simple test fix to take `java.lang.IdentityObject` interface into account until JDK-8247491 fixes
test/hotspot/jtreg/serviceability/jvmti/HiddenClass/P/Q/HiddenClassSigTest.java properly.

This will clear tier3 lworld test failure.

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Commit messages:
 - [lworld] temporary fix to HiddenClassSigTest test until JDK-8247491 updates the test properly
 - Merge
 - Merge
 - [lworld] misc reflection clean up
 - Merge
 - Post-merge adjustment in DirectMethodHandle

Changes: https://git.openjdk.java.net/valhalla/pull/98/files
 Webrev: https://webrevs.openjdk.java.net/valhalla/98/webrev.00
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/98.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/98/head:pull/98

PR: https://git.openjdk.java.net/valhalla/pull/98