hllSparseAdd(): speed optimization.
hllSparseAdd(): speed optimization.

Mostly by reordering opcodes check conditional by frequency of opcodes
in larger sparse-encoded HLLs.

MSOpenTech/redis,ttuna/msot-redis,jxwr/redis,HunanTV/redis,HunanTV/redis,ramonsnir/redis,ksarch-saas/redis,MSOpenTech/redis,darksideofthemoo/redis-histogram,ttuna/msot-redis,maodeyi/redis_lua,xuzhezhaozhao/redis_reading,splitice/redis,maodeyi/redis_lua,ksarch-saas/redis,MSOpenTech/redis,spearhead-ea/redis,Hailei/redis,slfs007/mk-redis,spearhead-ea/redis,ttuna/msot-redis,darksideofthemoo/redis-histogram,splitice/redis,himoca/redis,darksideofthemoo/redis-histogram,MSOpenTech/redis,louisliangjun/redis,ramonsnir/redis,spearhead-ea/redis,louisliangjun/redis,splitice/redis,ksarch-saas/redis,ramonsnir/redis,himoca/redis,xuzhezhaozhao/redis_reading,ttuna/msot-redis,HunanTV/redis,Hailei/redis,jxwr/redis,maodeyi/redis_lua,himoca/redis,louisliangjun/redis,splitice/redis,Hailei/redis,ttuna/msot-redis,ksarch-saas/redis,xuzhezhaozhao/redis_reading,jxwr/redis,MSOpenTech/redis,slfs007/mk-redis,Hailei/redis,HunanTV/redis,xuzhezhaozhao/redis_reading,slfs007/mk-redis,louisliangjun/redis,darksideofthemoo/redis-histogram