cmd/go: GOEXPERIMENT=gocacheprog [freeze exception]

[rsc]

Requesting a freeze exception for CL 486715 for Brad's GOEXPERIMENT=cacheprog work. It's clean and well isolated and doesn't affect anything unless you explicitly set GOEXPERIMENT=cacheprog. We want to make it available in Go 1.21 as an experiment in order to get feedback for promoting it to a real feature. Thanks.

[dmitshur]

Also copying @bradfitz's rationale from #60420:

I forgot to submit https://go-review.googlesource.com/c/go/+/486715 this morning after getting @bcmills's approval. I was going to spend the evening stress testing it more and then submit. I didn't know about this cycle's new freeze rules now including in-progress changes. 😬

CC @golang/release.

[dmitshur]

That CL has some comments that need to be resolved. It also says "Updates #59719"—is there more that needs to happen for that proposal or is that CL fine to submit now and leave further changes for 1.22?

[bradfitz]

It's all addressed now. I didn't say "Fixes" until it lands without an experiment, hopefully next cycle.

[bradfitz]

(but I can also say "Fixes" here and file a new bug later... no preference.)

[dmitshur]

The proposal was approved just today and this just missed the freeze by half an hour but is otherwise ready, so I can trivially approve this. Please feel free to go ahead with the CL, and thanks for letting us know.