runtime: only run TestNotInGoMetricCallback when building with cgo

It seems like some platforms don't build with cgo at all, like
linux/ppc64.

Change-Id: Ibe5306e79899822e77d42cb3018f9f0c9ca2604c
Reviewed-on: https://go-review.googlesource.com/c/go/+/728140
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>

2 files changed, 32 insertions, 20 deletions

diff --git a/src/runtime/metrics_cgo_test.go b/src/runtime/metrics_cgo_test.go
new file mode 100644
index 0000000000..6cc9d23195
--- /dev/null
+++ b/src/runtime/metrics_cgo_test.go
@@ -0,0 +1,32 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build cgo
+
+package runtime_test
+
+import (
+	"internal/race"
+	"runtime"
+	"testing"
+)
+
+func TestNotInGoMetricCallback(t *testing.T) {
+	switch runtime.GOOS {
+	case "windows", "plan9":
+		t.Skip("unsupported on Windows and Plan9")
+	case "freebsd":
+		if race.Enabled {
+			t.Skipf("race + cgo freebsd not supported. See https://go.dev/issue/73788.")
+		}
+	}
+
+	// This test is run in a subprocess to prevent other tests from polluting the metrics
+	// and because we need to make some cgo callbacks.
+	output := runTestProg(t, "testprogcgo", "NotInGoMetricCallback")
+	want := "OK\n"
+	if output != want {
+		t.Fatalf("output:\n%s\n\nwanted:\n%s", output, want)
+	}
+}
diff --git a/src/runtime/metrics_test.go b/src/runtime/metrics_test.go
index 278efdc69f..92cec75465 100644
--- a/src/runtime/metrics_test.go
+++ b/src/runtime/metrics_test.go
@@ -9,7 +9,6 @@ import (
 	"internal/abi"
 	"internal/goexperiment"
 	"internal/profile"
-	"internal/race"
 	"internal/testenv"
 	"os"
 	"reflect"
@@ -1585,22 +1584,3 @@ func TestReadMetricsSched(t *testing.T) {
 		t.Fatalf("output:\n%s\n\nwanted:\n%s", output, want)
 	}
 }
-
-func TestNotInGoMetricCallback(t *testing.T) {
-	switch runtime.GOOS {
-	case "windows", "plan9":
-		t.Skip("unsupported on Windows and Plan9")
-	case "freebsd":
-		if race.Enabled {
-			t.Skipf("race + cgo freebsd not supported. See https://go.dev/issue/73788.")
-		}
-	}
-
-	// This test is run in a subprocess to prevent other tests from polluting the metrics
-	// and because we need to make some cgo callbacks.
-	output := runTestProg(t, "testprogcgo", "NotInGoMetricCallback")
-	want := "OK\n"
-	if output != want {
-		t.Fatalf("output:\n%s\n\nwanted:\n%s", output, want)
-	}
-}