RFR: JDK-8266573: Make sure blackholes are tagged for all JVMCI paths

[Aleksey Shipilev]

In post-integration  https://github.com/openjdk/jdk/pull/2024#issuecomment-832834830, Tom says:
 "In this code, 6018336#diff-fa2433a762244542fec57f9d58dd3092bae74f354acf0ef33603a5f8306fd7daR995, the call to `CompilerOracle::tag_blackhole_if_possible` should be outside of the if. As written, methods won't be properly tagged for libgraal, only when used with the pure Java graal."

I am doing this blindly, because Graal is already removed from the codebase with JEP 410.

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Commit messages:
 - Move the tag upwards

Changes: https://git.openjdk.java.net/jdk/pull/3887/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3887&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266573
  Stats: 3 lines in 1 file changed: 2 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3887.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3887/head:pull/3887

PR: https://git.openjdk.java.net/jdk/pull/3887