RFR: 8292914: Drop the counter from lambda class names [v7]

[Brian Goetz]

On Fri, 17 Feb 2023 17:02:56 GMT, David M. Lloyd <duke at openjdk.org> wrote:

>> The class generated for lambda proxies is now defined as a hidden class. This means that the counter, which was used to ensure a unique class name and avoid clashes, is now redundant. In addition to performing redundant work, this also impacts build reproducibility for native image generators which might already have a strategy to cope with hidden classes but cannot cope with indeterminate definition order for lambda proxy classes.
>> 
>> This solves JDK-8292914 by making lambda proxy names always be stable without any configuration needed. This would also replace #10024.
>
> David M. Lloyd has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Updated to use hidden class suffix for dumps when possible, else use the counter with a `failed` suffix. Also, remove the extra trailing `$` from the lambda class name and update tests accordingly.
>   
>   This combines the suggestions made by @mlchung and @ExE-Boss and hopefully will resolve the Windows testing issue.

On 2/17/2023 12:50 PM, Ioi Lam wrote:
>
> If you really want a stable name, an alternative approach is to walk 
> the stack and find the caller of |LambdaMetafactory.metafactory| and 
> get the constant pool index of the invokedynamic instruction. (This 
> probably needs to be done with a native method).
>
> Javac uses a unique CP index for each call site (15 vs 23 in the 
> following example).
>

This is actually no longer true.  Liam @ Google did a "lambda 
deduplication" where multiple identical lambdas in a compilation unit 
are folded to a single index in the BSM, which can be used by multiple 
capturing indys.

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PR: https://git.openjdk.org/jdk/pull/12579