math/rand: deprecate Read
math/rand: deprecate Read

For #20661.

Change-Id: I1e638cb619e643eadc210d71f92bd1af7bafc912
Reviewed-on: https://go-review.googlesource.com/c/go/+/436955
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Run-TryBot: hopehook <63023fcaeafd0730eb709923fc3c0482e6977249@golangcn.org>
Auto-Submit: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Reviewed-by: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@google.com>
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>

golang/go,golang/go,golang/go,golang/go,golang/go,golang/go,golang/go,golang/go