[release-branch.go1.13] cmd/compile/internal/syntax: don't hardwire p…

…ath separator in test

Windows uses '\' not '/'.

For #35175.
Fixes #37901.

Change-Id: Ib3d01dcf148fc0675496d5213f5bcc9cf210a6fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/203889
Reviewed-by: Bryan C. Mills <[email protected]>
Run-TryBot: Brad Fitzpatrick <[email protected]>
(cherry picked from commit a754d29)
Reviewed-on: https://go-review.googlesource.com/c/go/+/223703
Reviewed-by: Robert Griesemer <[email protected]>
Run-TryBot: Andrew Bonventre <[email protected]>

src/cmd/compile/internal/syntax/parser_test.go

@@ -96,7 +96,7 @@ func walkDirs(t *testing.T, dir string, action func(string)) {
 			}
 		} else if fi.IsDir() && fi.Name() != "testdata" {
 			path := filepath.Join(dir, fi.Name())
-			if !strings.HasSuffix(path, "/test") {
+			if !strings.HasSuffix(path, string(filepath.Separator)+"test") {
 				dirs = append(dirs, path)
 			}
 		}