RFR: 8292914: Drop the counter from lambda class names [v5]

[Ioi Lam]

On Thu, 16 Feb 2023 14:06:54 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:
> 
>   Use `Instant.now()` for more precise timestamps.
>   
>   Using `currentTimeMillis` is imprecise enough that tests may sporadically fail if two lambda classes from the same lambda class are dumped within 1ms of one another. `Instant.now()` is much more precise and also sorts nicely.

Sorry, to be clear, I am not suggesting using a map for the proxy classes.

Instead, we should keep the existing logic that uses an AtomicInteger, but do this only when `-Djdk.internal.lambda.dumpProxyClasses=` is specified. That would be minimal change and we know it will surely work for people who are currently using this debugging property.

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