This test demonstrates diagnostics for various forms of file exclusion.

Skip on plan9, an arbitrary GOOS, so that we can exercise GOOS exclusions
resulting from file suffixes.

-- flags --
-min_go=go1.18
-skip_goos=plan9

-- go.work --
go 1.21

use (
	./a
)
-- a/go.mod --
module mod.com/a

go 1.18

-- a/a.go --
package a

-- a/a_plan9.go --
package a //@diag(re"package (a)", re"excluded due to its GOOS/GOARCH")

-- a/a_ignored.go --
//go:build skip
package a //@diag(re"package (a)", re"excluded due to its build tags")

-- b/go.mod --
module mod.com/b

go 1.18

-- b/b.go --
package b //@diag(re"package (b)", re"add this module to your go.work")

