text/template: error on range over send channel

text/template: error on range over send channel

template range require channel contains RecvDir
if recv on send only channel will raise an panic.

Fixes #43065

Change-Id: Ie0ea70ce60e074bf8c9f2378e07ef1d4c41dc38f
Reviewed-on: https://go-review.googlesource.com/c/go/+/276532
Trust: Meng Zhuo <mzh@golangcn.org>
Run-TryBot: Meng Zhuo <mzh@golangcn.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>