8325542: CTW: Runner can produce negative StressSeed

Reviewed-by: shade, xliu

Author: caojoshua

test/hotspot/jtreg/testlibrary/ctw/src/sun/hotspot/tools/ctw/CtwRunner.java

@@ -38,6 +38,7 @@
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Predicate;
+import java.util.Random;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
@@ -266,7 +267,7 @@ private Pair<String, Long> getLastClass(Path errFile) {
     private String[] cmd(long classStart, long classStop) {
         String phase = phaseName(classStart);
         Path file = Paths.get(phase + ".cmd");
-        var rng = Utils.getRandomInstance();
+        Random rng = Utils.getRandomInstance();
 
         ArrayList<String> Args = new ArrayList<String>(Arrays.asList(
                 "-Xbatch",
@@ -301,7 +302,7 @@ private String[] cmd(long classStart, long classStop) {
                 "-XX:+StressMacroExpansion",
                 "-XX:+StressIncrementalInlining",
                 // StressSeed is uint
-                "-XX:StressSeed=" + Math.abs(rng.nextInt())));
+                "-XX:StressSeed=" + rng.nextInt(Integer.MAX_VALUE)));
 
         for (String arg : CTW_EXTRA_ARGS.split(",")) {
             Args.add(arg);