cmd/go: replace TestCgoDependsOnSyscall with a simpler script test

The existing test attempted to remove '_race' binaries from
GOROOT/pkg, which could not only fail if GOROOT is read-only, but also
interfere with other tests run in parallel.

Updates #30316
Updates #37573
Updates #17751

Change-Id: Id7e2286ab67f8333baf4d52244b7f4476aa93a46
Reviewed-on: https://go-review.googlesource.com/c/go/+/223745
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/go/go_test.go

@@ -1545,34 +1545,6 @@ func TestSymlinkWarning(t *testing.T) {
 	tg.grepStderr("ignoring symlink", "list should have reported symlink")
 }
 
-func TestCgoDependsOnSyscall(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test that removes $GOROOT/pkg/*_race in short mode")
-	}
-	if !canCgo {
-		t.Skip("skipping because cgo not enabled")
-	}
-	if !canRace {
-		t.Skip("skipping because race detector not supported")
-	}
-
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.parallel()
-
-	files, err := filepath.Glob(filepath.Join(runtime.GOROOT(), "pkg", "*_race"))
-	tg.must(err)
-	for _, file := range files {
-		tg.check(robustio.RemoveAll(file))
-	}
-	tg.tempFile("src/foo/foo.go", `
-		package foo
-		//#include <stdio.h>
-		import "C"`)
-	tg.setenv("GOPATH", tg.path("."))
-	tg.run("build", "-race", "foo")
-}
-
 func TestCgoShowsFullPathNames(t *testing.T) {
 	if !canCgo {
 		t.Skip("skipping because cgo not enabled")

src/cmd/go/testdata/script/cgo_depends_on_syscall.txt

@@ -0,0 +1,11 @@
+[!cgo] skip
+[!race] skip
+
+go list -race -deps foo
+stdout syscall
+
+-- foo/foo.go --
+package foo
+
+// #include <stdio.h>
+import "C"