Add a XCTestCase based ObjC driver, SeqTest.m, to run the benchmarks package on iOS. While we're here, replace "Java" with "Foreign" in test names to reflect that benchmarks run on both platforms now. Change-Id: I38a38f3093b4b97961107b5ea66f03cff8e395c3 Reviewed-on: https://go-review.googlesource.com/20259 Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>