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

[Vladimir Kozlov]

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

@rose00 We have solution for that: we enforce encoding instructions (UseCompatibleCompressedOops flag) and use relocation info to patch correct COOP base address when loading AOT code.
The current issue is something changed in COOP code in runtime which cause next assert hit when we enforce encoding and use AOT code: [instanceKlass.cpp#L794](https://github.com/openjdk/leyden/blob/premain/src/hotspot/share/oops/instanceKlass.cpp#L794)

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PR Comment: https://git.openjdk.org/jdk/pull/25019#issuecomment-2861107654