increase number of realtime signals [PSARC/2010/062 Self Review]

[casper....@sun.com]

>Good.
>But the RFE I filed asked to set the number of real time signals to 64
>which does not require to change the definition of sigset_t.

Indeed; it seems that the userland sigset_t is 128 bits large (but the
kernel only uses 64)

Casper