* [RFC] Adding API for setting/getting benchmark_filter flag?
This PR is more of a Request-for-comment - open to other ideas/suggestions as well.
Details:
This flag has different implementations(absl vs benchmark) and since the proposal to add absl as a dependency was rejected, it would be nice to have a reliable (and less hacky) way to access this flag internally.
(Actually, reading it isn't much a problem but setting it is).
Internally, we have a sizeable number users to use absl::SetFlags to set this flag. This will not work with benchmark-flags.
Another motivation is that not all users use the command line flag. Some prefer to programmatically set this value.
* fixed build errors
* fix lints again
* per discussion: add additional RunSpecifiedBenchmarks instead.
* add tests
* fix up tests
* clarify comment
* fix stray : in test
* more assertion in test
* add test file to test/CMakeLists.txt
* more test
* make test ISO C++ compliant
* fix up BUILD file to pass the flag
