Fix assembler bug wrt negative constants
Fix assembler bug wrt negative constants

8l/kestrel,sam-falvo/kestrel,8l/kestrel,KestrelComputer/kestrel,8l/kestrel,8l/kestrel,KestrelComputer/kestrel,KestrelComputer/kestrel,KestrelComputer/kestrel,sam-falvo/kestrel,8l/kestrel,sam-falvo/kestrel,sam-falvo/kestrel,8l/kestrel