[lworld] RFR: 8274800: [lworld] Primitive classes can't be retransformed

[Alex Menkov]

Fix for java.lang.instrument.Instrumentation.retransformClasses()

Cases for retransformation primitive to identity (and identity to primitive) classes and changing primitive class fields (so default_value becomes invalid) are handled by existing code and spec changes are not required.

Also added serviceability test to hotspot_valhalla group

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Commit messages:
 - fixed tabs
 - retransformClasses fix

Changes: https://git.openjdk.java.net/valhalla/pull/588/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=588&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274800
  Stats: 522 lines in 6 files changed: 518 ins; 1 del; 3 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/588.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/588/head:pull/588

PR: https://git.openjdk.java.net/valhalla/pull/588