No benchmarks are run unless the --benchmarks=<regexp> flag
is specified on the gotest command line. This change includes
sample benchmarks for regexp.
% gotest --benchmarks=.*
(standard test output redacted)
testing.BenchmarkSimpleMatch 200000 7799 ns/op
testing.BenchmarkUngroupedMatch 20000 76898 ns/op
testing.BenchmarkGroupedMatch 50000 38148 ns/op
R=r, rsc
https://golang.org/cl/154173