[Isolates] Increase the isolate thread's stack size for tests.

samples/shell.cc

Index: samples/shell.cc
diff --git a/samples/shell.cc b/samples/shell.cc
index 3efd9dbb503e703416d5334ebb5f123c6ecce586..5d5ad4a1f8506fe85ed680ef381c68f346f411d3 100644
--- a/samples/shell.cc
+++ b/samples/shell.cc
@@ -109,7 +109,19 @@ class SourceGroup {
 
 #else
   void StartExecuteInThread() {
-    pthread_create(&thread_, NULL, &IsolateThreadEntry, this);
+    pthread_attr_t attr;
+    // On some systems (OSX 10.6) the stack size default is 0.5Mb or less
+    // which is not enough to parse the big literal expressions used in tests.
+    // The stack size should be at least StackGuard::kLimitSize + some
+    // OS-specific padding for thread startup code.
+    size_t stacksize = 1024 * 1024; // 1 Mb seems to be enough
+    pthread_attr_init(&attr);
+    pthread_attr_setstacksize (&attr, stacksize);
+    int error = pthread_create(&thread_, &attr, &IsolateThreadEntry, this);
+    if (error) {
+      printf("Error creating isolate thread.\n");
+      exit(1);
+    }
   }
 
   void WaitForThread() {