go/packages: drop pruned packages in tests of import graph

Explicitly listing the pruned packages ties the test to the details of
how the testing package is implemented. That shouldn't matter, and it
changes in CL 219639. This change makes it possible to work whether or
not CL 219639 is committed.

Updates golang/go#34129

Change-Id: I45875dadeaac42a1002e1329a1a762e340c5352c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221657
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Changkun Ou <euryugasaki@gmail.com>
Reviewed-by: Michael Matloob <matloob@golang.org>

go/packages/packages_test.go

@@ -139,9 +139,6 @@ func testLoadImportsGraph(t *testing.T, exporter packagestest.Exporter) {
   golang.org/fake/subdir/d [golang.org/fake/subdir/d.test] -> math/bits
   golang.org/fake/subdir/d.test -> golang.org/fake/subdir/d [golang.org/fake/subdir/d.test]
   golang.org/fake/subdir/d.test -> golang.org/fake/subdir/d_test [golang.org/fake/subdir/d.test]
-  golang.org/fake/subdir/d.test -> os (pruned)
-  golang.org/fake/subdir/d.test -> testing (pruned)
-  golang.org/fake/subdir/d.test -> testing/internal/testdeps (pruned)
   golang.org/fake/subdir/d_test [golang.org/fake/subdir/d.test] -> golang.org/fake/subdir/d [golang.org/fake/subdir/d.test]
 `[1:]
 
@@ -178,9 +175,6 @@ func testLoadImportsGraph(t *testing.T, exporter packagestest.Exporter) {
   golang.org/fake/subdir/d [golang.org/fake/subdir/d.test] -> math/bits
   golang.org/fake/subdir/d.test -> golang.org/fake/subdir/d [golang.org/fake/subdir/d.test]
   golang.org/fake/subdir/d.test -> golang.org/fake/subdir/d_test [golang.org/fake/subdir/d.test]
-  golang.org/fake/subdir/d.test -> os (pruned)
-  golang.org/fake/subdir/d.test -> testing (pruned)
-  golang.org/fake/subdir/d.test -> testing/internal/testdeps (pruned)
   golang.org/fake/subdir/d_test [golang.org/fake/subdir/d.test] -> golang.org/fake/subdir/d [golang.org/fake/subdir/d.test]
 `[1:]
 
@@ -259,9 +253,6 @@ func testLoadImportsGraph(t *testing.T, exporter packagestest.Exporter) {
   golang.org/fake/subdir/d [golang.org/fake/subdir/d.test] -> math/bits
   golang.org/fake/subdir/d.test -> golang.org/fake/subdir/d [golang.org/fake/subdir/d.test]
   golang.org/fake/subdir/d.test -> golang.org/fake/subdir/d_test [golang.org/fake/subdir/d.test]
-  golang.org/fake/subdir/d.test -> os (pruned)
-  golang.org/fake/subdir/d.test -> testing (pruned)
-  golang.org/fake/subdir/d.test -> testing/internal/testdeps (pruned)
   golang.org/fake/subdir/d_test [golang.org/fake/subdir/d.test] -> golang.org/fake/subdir/d [golang.org/fake/subdir/d.test]
 `[1:]
 
@@ -303,9 +294,6 @@ func testLoadImportsTestVariants(t *testing.T, exporter packagestest.Exporter) {
   golang.org/fake/a [golang.org/fake/b.test] -> golang.org/fake/b [golang.org/fake/b.test]
   golang.org/fake/b.test -> golang.org/fake/b [golang.org/fake/b.test]
   golang.org/fake/b.test -> golang.org/fake/b_test [golang.org/fake/b.test]
-  golang.org/fake/b.test -> os (pruned)
-  golang.org/fake/b.test -> testing (pruned)
-  golang.org/fake/b.test -> testing/internal/testdeps (pruned)
   golang.org/fake/b_test [golang.org/fake/b.test] -> golang.org/fake/a [golang.org/fake/b.test]
 `[1:]
 
@@ -2672,7 +2660,6 @@ func importGraph(initial []*packages.Package) (string, map[string]*packages.Pack
 				if isTestMain {
 					switch imp.ID {
 					case "os", "reflect", "testing", "testing/internal/testdeps":
-						edges = append(edges, fmt.Sprintf("%s -> %s (pruned)", p, imp))
 						continue
 					}
 				}