RFR: 8354887: Preserve runtime blobs in AOT code cache [v2]

[Andrew Dinn]

On Mon, 5 May 2025 21:13:24 GMT, Ashutosh Mehra <asmehra at openjdk.org> wrote:

>> [8350209](https://bugs.openjdk.org/browse/JDK-8350209) introduced the framework for storing code in aot code cache and used it for caching i2c/c2i adapters.
>> This PR extends the `AOTCodeCache` infrastructure and stores various runtime blobs (shared blobs, C1 and C2 runtime blobs) in the AOT code cache. It adds a new diagnostic flag `AOTStubCaching` to enable/disable the caching of these blobs.
>> `AOTCodeFlags.java` test is extended to cover `AOTStubCaching`.
>
> Ashutosh Mehra has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 11 commits:
> 
>  - Merge branch 'master' into preserve-runtime-blobs-master
>  - Address Vladimir's comments
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Remove irrelevant comment
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Fix win64 compile failures
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Fix AOTCodeFlags.java test
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Fix compile failure in minimal config
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Revert back changes that added AOTRuntimeConstants.
>    Ensure CompressedOops::base and CompressedKlssPointers::base does not
>    change in production run
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Fix merge conflicts
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Store/load AsmRemarks and DbgStrings in aot code cache
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - Add missing external address in aarch64
>    
>    Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>
>  - ... and 1 more: https://git.openjdk.org/jdk/compare/2a4f37cc...ba612dab

I looked back at the history and found that this line got commented out as part of a merge from mainline (date: 2025-01-15 shaid 4cd4c7cdfae7b4b5eb3308abc8fa8d0ed7581ad8).

I'm not at all sure why Ioi did this and have no idea why he added my name to the original FIXME. The very next change he made in the premain branch was to update the FIXME comment, resetting it to his name.

I also don't understand why this is not biting us in premain.

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PR Comment: https://git.openjdk.org/jdk/pull/25019#issuecomment-2859254016