cmd/compile: require 'go 1.16' go.mod line for //go:embed
This will produce better errors when earlier versions of
Go compile code using //go:embed. (The import will cause
a compilation error but then the go command will add to
the output that the Go toolchain in use looks too old
and maybe that's the problem.)
This CL also adds a test for disallowing embed of a var inside a func.
It's a bit too difficult to rebase down into that CL.
The build system configuration check is delayed in order to
make it possible to use errorcheck for these tests.
Change-Id: I12ece4ff2d8d53380b63f54866e8f3497657d54c
Reviewed-on: https://go-review.googlesource.com/c/go/+/282718
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>