Set the default allocation size request to 4MB

DefineOptions.cmake

@@ -60,7 +60,7 @@ endif (LEON3)
 
 if (LINUXTEST)
   set(WITH_SYSTEM_CALLS "mmap")
-  set(SYS_ALLOC_SIZE 60000)
+  set(SYS_ALLOC_SIZE 4194304)
   set(WITH_FIXED_LISTS OFF)
   set(SORT_POLICY "lifo")
   set(SEARCH_POLICY "first")