RFR: JDK-8273914: Indy string concat changes order of operations [v5]

[Jan Lahoda]

On Thu, 14 Oct 2021 17:14:42 GMT, Liam Miller-Cushon <cushon at openjdk.org> wrote:

>> This change makes string concatenation call `toString` on the arguments eagerly, to preserve the correct evaluation order of the arguments and the calls to `toString`.
>
> Liam Miller-Cushon has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rename WellKnownTypes to WellKnownTypeSignatures
>   
>   and add more functional test coverage for string concat of well-known
>   types, covering all strategies.

Looks reasonable.

-------------

Marked as reviewed by jlahoda (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/5844