Fix incrDecrCommand() to create shared objects when needed.
Fix incrDecrCommand() to create shared objects when needed.

See #5011.

soloestoy/redis,nnog/redis,soveran/redis,ctripcorp/redis,charsyam/redis,PKRoma/redis,neomantra/redis,yossigo/redis,antirez/redis,nnog/redis,PKRoma/redis,yossigo/redis,charsyam/redis,pmem/redis,pmem/redis,spinlock/redis,ofirluzon/redis,oranagra/redis,yossigo/redis,GitHubMota/redis,ofirluzon/redis,PKRoma/redis,soveran/redis,charsyam/redis,neomantra/redis,nnog/redis,GitHubMota/redis,nnog/redis,ctripcorp/redis,oranagra/redis,soloestoy/redis,yossigo/redis,antirez/redis,antirez/redis,soloestoy/redis,PKRoma/redis,GitHubMota/redis,yossigo/redis,soloestoy/redis,GitHubMota/redis,soveran/redis,pmem/redis,oranagra/redis,ofirluzon/redis,oranagra/redis,soloestoy/redis,neomantra/redis,neomantra/redis,charsyam/redis,ctripcorp/redis,spinlock/redis,charsyam/redis,PKRoma/redis,soveran/redis,ofirluzon/redis,neomantra/redis,spinlock/redis,spinlock/redis,ofirluzon/redis,antirez/redis,ctripcorp/redis,oranagra/redis,pmem/redis