reduce sigset_t size for 128 bytes to 64 bits:

reduce sigset_t size for 128 bytes to 64 bits:

    text           data     bss     dec     hex filename
-  38457          18352    8636   65445    ffa5 lib/libpthread-0.9.30-svn.so
+  38015          18096    8636   64747    fceb lib/libpthread-0.9.30-svn.so
-   8205            280      12    8497    2131 lib/libthread_db-0.9.30-svn.so
+   8193            280      12    8485    2125 lib/libthread_db-0.9.30-svn.so
- 275208           1823   19132  296163   484e3 lib/libuClibc-0.9.30-svn.so
+ 274787           1823   19012  295622   482c6 lib/libuClibc-0.9.30-svn.so