Fix running JDWP tests on Windows

Bug: 64596150
Change-Id: I1417de1849c5ee50baa21ee4b50907a3a5925e14
diff --git a/src/test/java/com/android/tools/r8/jdwp/RunJdwpTests.java b/src/test/java/com/android/tools/r8/jdwp/RunJdwpTests.java
index 6ee0b66..a71291d 100644
--- a/src/test/java/com/android/tools/r8/jdwp/RunJdwpTests.java
+++ b/src/test/java/com/android/tools/r8/jdwp/RunJdwpTests.java
@@ -205,7 +205,7 @@
       String pkg = "org.apache.harmony.jpda.tests.jdwp";
       command = Arrays.asList(
           ToolHelper.getJavaExecutable(),
-          "-cp", System.getProperty("java.class.path") + ":" + lib,
+          "-cp", System.getProperty("java.class.path") + File.pathSeparator + lib,
           run, pkg + "." + test);
     } else {
       command = Arrays.asList(