Add more protection against exited processed in CoreclrTestLib (#115642)

* Add more protection against exited processed in CoreclrTestLib
* Update src/tests/Common/Coreclr.TestWrapper/CoreclrTestWrapperLib.cs

Author: jkotas

src/tests/Common/Coreclr.TestWrapper/CoreclrTestWrapperLib.cs

@@ -681,15 +681,25 @@ public static bool TryPrintStackTraceFromDmp(string dmpFile, TextWriter outputWr
         // The children are sorted in the order they should be dumped
         static unsafe IEnumerable<Process> FindChildProcessesByName(Process process, string childName)
         {
-            Console.WriteLine($"Finding all child processes of '{process.ProcessName}' (ID: {process.Id}) with name '{childName}'");
+            process.TryGetProcessName(out string parentProcessName);
+            process.TryGetProcessId(out int parentProcessId);
+            Console.WriteLine($"Finding all child processes of '{parentProcessName}' (ID: {parentProcessId}) with name '{childName}'");
 
             var children = new Stack<Process>();
             Queue<Process> childrenToCheck = new Queue<Process>();
             HashSet<int> seen = new HashSet<int>();
 
-            seen.Add(process.Id);
-            foreach (var child in process.GetChildren())
-                childrenToCheck.Enqueue(child);
+            seen.Add(parentProcessId);
+
+            try
+            {
+                foreach (var child in process.GetChildren())
+                    childrenToCheck.Enqueue(child);
+            }
+            catch
+            {
+                // Process exited
+            }
 
             while (childrenToCheck.Count != 0)
             {
@@ -707,8 +717,15 @@ static unsafe IEnumerable<Process> FindChildProcessesByName(Process process, str
                 Console.WriteLine($"Checking child process: '{processName}' (ID: {processId})");
                 seen.Add(processId);
 
-                foreach (var grandchild in child.GetChildren())
-                    childrenToCheck.Enqueue(grandchild);
+                try
+                {
+                    foreach (var grandchild in child.GetChildren())
+                        childrenToCheck.Enqueue(grandchild);
+                }
+                catch
+                {
+                    // Process exited
+                }
 
                 if (processName.Equals(childName, StringComparison.OrdinalIgnoreCase))
                 {
@@ -844,7 +861,9 @@ public int RunTest(string executable, string outputFile, string errorFile, strin
                         Console.WriteLine($"\t{"ID",-6} ProcessName");
                         foreach (var activeProcess in Process.GetProcesses())
                         {
-                            Console.WriteLine($"\t{activeProcess.Id,-6} {activeProcess.ProcessName}");
+                            activeProcess.TryGetProcessName(out string activeProcessName);
+                            activeProcess.TryGetProcessId(out int activeProcessId);
+                            Console.WriteLine($"\t{activeProcessId,-6} {activeProcessName}");
                         }
 
                         if (OperatingSystem.IsWindows())