RFR: 8254842: [JVMCI] copy thread name when attaching libgraal thread to HotSpot

[Doug Simon]

This PR modifies `HotSpotJVMCIRuntime.attachCurrentThread` when it is called from within libgraal so that the name of
the thread in the libgraal heap is used as the name of the peer thread created in HotSpot.

This useful when viewing output such as `-XX:JVMCITraceLevel=1`. For example, here's sample output without this PR:
JVMCITrace-1[Thread-0]: initializing JVMCI runtime -1
JVMCITrace-1[Thread-0]: initialized JVMCI runtime -1
and then with:
JVMCITrace-1[LibGraalHotSpotGraalManagementInitialization]: initializing JVMCI runtime -1
JVMCITrace-1[LibGraalHotSpotGraalManagementInitialization]: initialized JVMCI runtime -1

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Commit messages:
 - 8254842: [JVMCI] copy thread name when attaching libgraal thread to HotSpot

Changes: https://git.openjdk.java.net/jdk/pull/684/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=684&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8254842
  Stats: 18 lines in 3 files changed: 12 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/684.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/684/head:pull/684

PR: https://git.openjdk.java.net/jdk/pull/684