net/http: use Copy in ServeContent if CopyN not needed
This small PR allows optimizations made in io.Copy (like the use of
io.WriterTo) to be used in one possible path of http.ServeContent
(in case of a non-Range request).
This, in turn, allows us to skip the buffer allocation in io.Copy.
Change-Id: Ifa2ece206ecd4556aaaed15d663b65e95e00bb0a
GitHub-Last-Rev:
94fc0318145ba1bd48502564f6488aade871c301
GitHub-Pull-Request: golang/go#56480
Reviewed-on: https://go-review.googlesource.com/c/go/+/446276
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>