We currently support running jtreg tests in "AOT" mode. In this mode, we create a custom AOT cache during the setup phase of "make test JTREG_AOT_JDK=true ...", and then add the location of this AOT cache:

https://github.com/openjdk/jdk/blob/de3a218a2801b8a4b414fce9337bd151ded9b7f8/make/RunTests.gmk#L955
   $1_JTREG_BASIC_OPTIONS += -vmoption:-XX:AOTCache="$$($1_AOT_JDK_CACHE)"

This custom AOT cache includes many classes from the JDK (such as Javac, etc), so we can increase the coverage of AOT.

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Proposal: instead of creating this cache during test set up, we create a set of custom AOT caches during the JDK build and store them in the test-image.
- This can be part of sanity test during the build
- reduce set up time of individual test tasks
- the custom cache is available for diagnosing failures.