[jdk21] RFR: 8313241: Temporarily disable "malformed control flow" assert to reduce noise

[Tobias Hartmann]

[JDK-8303951](https://bugs.openjdk.org/browse/JDK-8303951) added asserts before several C2 compilation bailouts that we were never able to trigger in our testing. The "malformed control flow" assert now triggers regularly (see [JDK-8308392](https://bugs.openjdk.org/browse/JDK-8308392) and [JDK-8312980](https://bugs.openjdk.org/browse/JDK-8312980)). Let's disable it in JDK 21 to reduce the noise in the CI.

I also reverted the problem listing done by [JDK-8313208](https://bugs.openjdk.org/browse/JDK-8313208) because, as @AlanBateman noted in https://github.com/openjdk/jdk21/pull/145, it's too invasive.

Approval is pending.

Thanks,
Tobias

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Commit messages:
 - 8313241: Temporarily disable "malformed control flow" assert to reduce noise

Changes: https://git.openjdk.org/jdk21/pull/146/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21&pr=146&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313241
  Stats: 2 lines in 2 files changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk21/pull/146.diff
  Fetch: git fetch https://git.openjdk.org/jdk21.git pull/146/head:pull/146

PR: https://git.openjdk.org/jdk21/pull/146