[jdk16] RFR: 8258558: Revert changes for JDK-8252505 and related issues

[Aleksey Shipilev]

As the result of retroactive CSR discussion in JDK-8257827, I have decided to revert the original push and all the follow-up changes from JDK 16, in order to reconsider them for JDK 17.

This PR reverts the following changes -- the reversal is clean and done without manual intervention:
  JDK-8258111: Problemlist compiler/blackhole tests for -Xcomp until JDK-8258101 is fixed
  JDK-8257848: -XX:CompileCommand=blackhole,* should be diagnostic
  JDK-8257805: Add compiler/blackhole tests to tier1
  JDK-8257803: Add -Xbatch to compiler/blackhole tests
  JDK-8252505: C1/C2 compiler support for blackholes

While line count is great, the overwhelming majority of changes are test removals.

Additional testing:
 - [x] Linux x86_64 `tier1`

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Commit messages:
 - 8258558: Revert changes for JDK-8252505

Changes: https://git.openjdk.java.net/jdk16/pull/86/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=86&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258558
  Stats: 1662 lines in 33 files changed: 0 ins; 1660 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk16/pull/86.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/86/head:pull/86

PR: https://git.openjdk.java.net/jdk16/pull/86