RFR: 8292679: Simplify thread creation in gtest and port 2 tests to new way

[Thomas Stuefe]

On Mon, 22 Aug 2022 10:53:27 GMT, Johan Sjölén <duke at openjdk.org> wrote:

> This PR removes a lot of boilerplate that was required when creating multi-threaded tests and ports 2 tests to show that the number of lines of code is significantly reduced and that porting is fairly trivial. The ported tests also serve as an introduction to others who're looking into writing their own multi-threaded tests.
> 
> Testing: Ran the ported tests on my machine, also running the tests on x64 {Windows, Linux, Mac OS X],  aarch64 { Linux, Mac OS X} and tier1 for "completeness".

p.s. sorry for sounding grumpy, that was not my intention. The reduction in LOC is certainly nice. I just would like it if a look at an API would make it clear to me how it is to be used. In this case, e.g., what purpose state and state generator have and what methods they should implement.

Thank you.

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

PR: https://git.openjdk.org/jdk/pull/9962