Resource Limits

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
Store old RC in update frame.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
Improved sanity checking for RC invariants.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
Implement the primops and source-language support.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
Wire up prim-ops to use cmmMaybeAllocate

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>