bytes: document that Reader.Reset affects the result of Size
The Reader.Reset changes the underlying byte slice, so it actually
changes the return value of the Size method.
Fixes #54018
Change-Id: I160deaa2244e95cb93303cb5dfb67a8d90a375ef
GitHub-Last-Rev:
b04724a072d956db1f84a8f5db0afa0dbb158e96
GitHub-Pull-Request: golang/go#54020
Reviewed-on: https://go-review.googlesource.com/c/go/+/419237
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>