RFR: [lworld] Switch JLink to not use ImageReader API [v2]

[David Beaumont]

On Wed, 5 Nov 2025 00:08:05 GMT, David Beaumont <duke at openjdk.org> wrote:

>> David Beaumont has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Remove redundant extra method (part of original prototype)
>
> test/jdk/tools/jlink/runtimeImage/PackagedModulesVsRuntimeImageLinkTest.java line 148:
> 
>> 146:     }
>> 147: 
>> 148:     // Helper to assert the content of two jimage files are the same and provide
> 
> This is an optional (but nice) improvement to how the test reported mismatched lists of entries.
> Without it, the test just fails with no useful output.
> If anyone knows a neater way (e.g. some set difference methods) then I'll happily neaten this up.

I tidied it up (should have done this from the start).

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PR Review Comment: https://git.openjdk.org/valhalla/pull/1721#discussion_r2494721587