Go now includes the GOROOT bin directory in $PATH while running tests
and generate, so it is no longer necessary to construct a path using
runtime.GOROOT().
Fixes#6689
Signed-off-by: James Tucker <james@tailscale.com>
rsc.io/goversion is really expensive.
Running version.ReadExe on tailscaled on darwin
allocates 47k objects, almost 11mb.
All we want is the module info. For that, all we need to do
is scan through the binary looking for the magic start/end strings
and then grab the bytes in between them.
We can do that easily and quickly with nothing but a 64k buffer.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>