libc had some -Wimplicit-fallthrough warnings. They all seem to be
benign. We're trying to enable this flag globally, so we need to
annotate these breaks here.
Bug: 112564944
Test: Builds
Change-Id: I5afae694cc4cf26ad1a61e2c8ae91f00cda7c733
Makes no difference to the benchmarks, but does make the code a bit
more readable.
Bug: http://b/68672236
Test: ran tests, benchmarks
Change-Id: I63fa5f78d077c86e4f4f194f2c76ab5510c29109
