go/packages: fix tests on 1.10

Can't do module tests on a pre-modules version of Go.

Change-Id: I8e3e22d472f37ebc9f930a68c9a6c0f4b7ba7ea0
Reviewed-on: https://go-review.googlesource.com/c/142700
Run-TryBot: Heschi Kreinick <heschi@google.com>
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
diff --git a/go/packages/packages_test.go b/go/packages/packages_test.go
index 5f14d88..85fac18 100644
--- a/go/packages/packages_test.go
+++ b/go/packages/packages_test.go
@@ -1138,6 +1138,10 @@
 }
 
 func TestName_Modules(t *testing.T) {
+	if usesOldGolist {
+		t.Skip("pre-modules version of Go")
+	}
+
 	tmp, cleanup := makeTree(t, map[string]string{
 		"src/localmod/go.mod":     `module test`,
 		"src/localmod/pkg/pkg.go": `package pkg;`,
@@ -1174,6 +1178,10 @@
 }
 
 func TestName_ModulesDedup(t *testing.T) {
+	if usesOldGolist {
+		t.Skip("pre-modules version of Go")
+	}
+
 	tmp, cleanup := makeTree(t, map[string]string{
 		"src/localmod/go.mod": `module test`,
 	})