RFR: Update nmethod caching and clean up unused/duplicate methods [v3]

[Vladimir Kozlov]

On Mon, 2 Jun 2025 14:51:47 GMT, Ashutosh Mehra <asmehra at openjdk.org> wrote:

>> This PR updates nmethod caching to be based on caching of CodeBlob. It also cleans up some dead code and duplicate methods.
>
> Ashutosh Mehra has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove CodeBuffer::clear_strings() as the relevant destructors clear the
>   strings
>   
>   Signed-off-by: Ashutosh Mehra <asmehra at redhat.com>

And we need to fix bootstrap sequence: [JDK-8358690](https://bugs.openjdk.org/browse/JDK-8358690) and https://github.com/openjdk/leyden/pull/75

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PR Comment: https://git.openjdk.org/leyden/pull/71#issuecomment-2945156433