reflect: add a copy of BenchmarkMap

This is a copy of reflect_test.BenchmakMap from the Go standard library,
added in

This is added to x/benchmarks only temporarily as a sample 'go test'
benchmark to use with benchmarking tools. This benchmark was selected in
particular because it had a significant performance improvement with a
recent upstream change (

Change-Id: I2bff47ffbaab1d471a37ec3cba4bea88cc78d8ed
Trust: Michael Pratt <>
Run-TryBot: Michael Pratt <>
Reviewed-by: Michael Knyszek <>
TryBot-Result: Go Bot <>
1 file changed