Increase default thread stack size to 64k and institute crude
overflow checks in scheduler_sanity().


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@183 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/vg_include.h b/vg_include.h
index 1249d11..b71a101 100644
--- a/vg_include.h
+++ b/vg_include.h
@@ -142,6 +142,10 @@
    knows.) */
 #define VG_N_WAITING_FDS 10
 
+/* Stack size for a thread.  We try and check that they do not go
+   beyond it. */
+#define VG_PTHREAD_STACK_SIZE 65536
+
 
 /* ---------------------------------------------------------------------
    Basic types