RFR: 8316453: [JVMCI] Using Xcomp on jargraal must eagerly initialize JVMCI

[Doug Simon]

This PR fixes the behavior of jargraal under `-Xcomp` such that compilations of methods executed after VM startup are blocking compilations.

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Commit messages:
 - force eager JVMCI initialization in jargraal with -Xcomp

Changes: https://git.openjdk.org/jdk/pull/15801/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15801&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316453
  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15801.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15801/head:pull/15801

PR: https://git.openjdk.org/jdk/pull/15801