Reduce signal sender thread stack size to 32k.

src/snapshot.h

Index: src/snapshot.h
===================================================================
--- src/snapshot.h	(revision 10368)
+++ src/snapshot.h	(working copy)
@@ -26,6 +26,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "isolate.h"
+#include "spaces.h"
 
 #ifndef V8_SNAPSHOT_H_
 #define V8_SNAPSHOT_H_
@@ -86,6 +87,21 @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(Snapshot);
 };
 
+
+// These are the sizes of the spaces that are needed in order to unpack the
+// VM boot snapshot.
+const int kMinimumSpaceSizes[LAST_SPACE + 1] = {
+  0,           // New space.
+  512 * 1024,  // Old pointer space.
+  128 * 1024,  // Old data space.
+  256 * 1024,  // Code space.
+  64 * 1024,   // Map space.
+  64 * 1024,   // Cell space.
+  0            // Large object space.
+};
+
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_SNAPSHOT_H_