Fix MaxWorkingSet_GetNotStarted_ThrowsInvalidOperationException

Author: gwr

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.BSD.cs

@@ -57,6 +57,8 @@ private static IntPtr ProcessorAffinityCore
         /// </summary>
         private void GetWorkingSetLimits(out IntPtr minWorkingSet, out IntPtr maxWorkingSet)
         {
+            EnsureState(State.HaveNonExitedId);
+
             // We can only do this for the current process on OS X
             if (_processId != Environment.ProcessId)
                 throw new PlatformNotSupportedException(SR.OsxExternalProcessWorkingSetNotSupported);
@@ -86,6 +88,8 @@ private void GetWorkingSetLimits(out IntPtr minWorkingSet, out IntPtr maxWorking
         /// <param name="resultingMax">The resulting maximum working set limit after any changes applied.</param>
         private void SetWorkingSetLimitsCore(IntPtr? newMin, IntPtr? newMax, out IntPtr resultingMin, out IntPtr resultingMax)
         {
+            EnsureState(State.HaveNonExitedId);
+
             // We can only do this for the current process on OS X
             if (_processId != Environment.ProcessId)
                 throw new PlatformNotSupportedException(SR.OsxExternalProcessWorkingSetNotSupported);