The benchmark currently uses makeCartesianProductBenchmark, which
doesn't make a ton of sense, since minmax_element always goes through
every element one by one. The runtime doesn't depend on the values
of the elements.
Fixes#120758
This patch fixes warnings and errors that come up when running the
benchmarks as part of the test suite. It also adds the necessary Lit
annotations to make it pass in various configurations and increases the
portability of the benchmarks.
This is an intermediate and fairly mechanical step towards unifying the
benchmarks with the rest of the test suite. Moving this around requires
a few changes, notably making sure we don't throw a wrench into the
discovery process of the normal test suite. This won't be a problem
anymore once benchmarks are taken into account by the test setup out of
the box.
