Revert "cmd/dist: consolidate runtime CPU tests"

This reverts commit a9e50a6b.

Change-Id: I3c5e459f1030e36bc249910facdae12303a44151
Reviewed-on: https://go-review.googlesource.com/9394Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

src/cmd/dist/test.go

@@ -199,18 +199,21 @@ func (t *tester) registerTests() {
 	}
 
 	// Runtime CPU tests.
-	testName := "runtime:cpu124"
+	for _, cpu := range []string{"1", "2", "4"} {
+		cpu := cpu
+		testName := "runtime:cpu" + cpu
 		t.tests = append(t.tests, distTest{
 			name:    testName,
 			heading: "GOMAXPROCS=2 runtime -cpu=1,2,4",
 			fn: func() error {
-			cmd := t.dirCmd("src", "go", "test", "-short", t.timeout(300), "runtime", "-cpu=1,2,4")
+				cmd := t.dirCmd("src", "go", "test", "-short", t.timeout(300), "runtime", "-cpu="+cpu)
 				// We set GOMAXPROCS=2 in addition to -cpu=1,2,4 in order to test runtime bootstrap code,
 				// creation of first goroutines and first garbage collections in the parallel setting.
 				cmd.Env = mergeEnvLists([]string{"GOMAXPROCS=2"}, os.Environ())
 				return cmd.Run()
 			},
 		})
+	}
 
 	// sync tests
 	t.tests = append(t.tests, distTest{