add test provider bin for e2etest

One e2etest still requires the bin, so add that back temporarily.

command/e2etest/provider_dev_test.go

@@ -33,7 +33,7 @@ func TestProviderDevOverrides(t *testing.T) {
 	// such as if it stops being buildable into an independent executable.
 	providerExeDir := filepath.Join(tf.WorkDir(), "pkgdir")
 	providerExePrefix := filepath.Join(providerExeDir, "terraform-provider-test_")
-	providerExe := e2e.GoBuild("github.com/hashicorp/terraform/builtin/bins/provider-test", providerExePrefix)
+	providerExe := e2e.GoBuild("github.com/hashicorp/terraform/internal/legacy/builtin/bins/provider-test", providerExePrefix)
 	t.Logf("temporary provider executable is %s", providerExe)
 
 	err := ioutil.WriteFile(filepath.Join(tf.WorkDir(), "dev.tfrc"), []byte(fmt.Sprintf(`

internal/legacy/builtin/bins/provider-test/main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"github.com/hashicorp/terraform/internal/legacy/builtin/providers/test"
+	"github.com/hashicorp/terraform/internal/legacy/terraform"
+	"github.com/hashicorp/terraform/plugin"
+)
+
+func main() {
+	plugin.Serve(&plugin.ServeOpts{
+		ProviderFunc: func() terraform.ResourceProvider {
+			return test.Provider()
+		},
+	})
+}