Open a capability receive window according to the number of the capabilities
expected as out parameter per RPC function.
Typically the number of capabilities expected during the reply of a RPC/IPC
call is 0 to 1. Before this patch ever a capability receive window of 4 has
been opened.
On Nova the capability selectors of receive windows must be naturally aligned
to the size/order of the expected capabilities. This leads until now to the
issue that the left over 3 capabilities couldn't be reused for new IPCs since
they are not naturally aligned to 4.
Issue #905
1dd2a199a5