Speculative fix for MultithreadedParallelIsolates on ARM

test/cctest/test-lockers.cc

Index: test/cctest/test-lockers.cc
diff --git a/test/cctest/test-lockers.cc b/test/cctest/test-lockers.cc
index ba0fdb22066a89bbba9f3e6c564479bab77ac13f..5b33f2ee06b7f8e50ca8ca46eb3f18b6424d97c7 100644
--- a/test/cctest/test-lockers.cc
+++ b/test/cctest/test-lockers.cc
@@ -240,7 +240,11 @@ class IsolateNonlockingThread : public JoinableThread {
 
 // Run many threads each accessing its own isolate without locking
 TEST(MultithreadedParallelIsolates) {
+#ifdef V8_TARGET_ARCH_ARM
+  const int kNThreads = 10;
+#else
   const int kNThreads = 50;
+#endif
   i::List<JoinableThread*> threads(kNThreads);
   for (int i = 0; i < kNThreads; i++) {
     threads.Add(new IsolateNonlockingThread());