RFR: 8348570: CTW: Expose the code hidden by uncommon traps

[Aleksey Shipilev]

We have been looking at some related compiler behaviors, and realized that in the absence of profiling data, C2 routinely uncommon-traps a lot of code that is presumed to be never executed. This apparently is a norm in CTW tests: CTW runners never execute code, and so only the most basic java.base classes are having any profile. This seems to limit the scope of CTW testing.

I think we need to run CTW in the mode that exposes more code to the compiler optimizations.

Case in point: [JDK-8348572](https://bugs.openjdk.org/browse/JDK-8348572), which reliably fails with more aggressive compilation mode. We cannot integrate this PR until that bug is fixed. But we can discuss if this makes sense, and/or we want some other options included to expand CTW testing.

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/23296/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23296&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8348570
  Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23296.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23296/head:pull/23296

PR: https://git.openjdk.org/jdk/pull/23296