RFR: 8341696: C2: Non-fluid StringBuilder pattern bails out in OptoStringConcat [v9]

[Vladimir Kozlov]

On Tue, 21 Jan 2025 14:02:00 GMT, Theo Weidmann <tweidmann at openjdk.org> wrote:

>> Extends stringopts to also recognize non-fluid uses of StringBuilder and optimize them the same way.
>> 
>> For example, this basic case was not optimized before and is optimized with this PR:
>> 
>> 
>> StringBuilder sb = new StringBuilder();
>> sb.append("a");
>> sb.append(a);
>> return sb.toString();
>
> Theo Weidmann has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix merge gone wrong

Re-approved after merge.

@theoweidmannoracle, I see failures in your latest internal testing.

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Marked as reviewed by kvn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22537#pullrequestreview-2565395118
Changes requested by kvn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22537#pullrequestreview-2565401076