future: sprinke always_inline attributes in strategic places
future: sprinke always_inline attributes in strategic places

gcc makes poor inlining decisions sometimes, which cause all the value-
tracking optimizations to be lost.  Forcing it to inline (particularly
around destructors) allows ready futures to be inlined with fewer always-
true tests and data movements.

kjniemi/scylla,jonathanleang/seastar,wildinto/seastar,stamhe/scylla,stamhe/seastar,joerg84/seastar,shyamalschandra/seastar,kjniemi/seastar,justintung/scylla,aruanruan/scylla,avikivity/scylla,respu/scylla,xtao/seastar,flashbuckets/seastar,rluta/scylla,tempbottle/seastar,bowlofstew/scylla,wildinto/scylla,linearregression/scylla,scylladb/scylla,syuu1228/seastar,cloudius-systems/seastar,scylladb/scylla,kjniemi/scylla,linearregression/scylla,kangkot/scylla,tempbottle/seastar,bowlofstew/scylla,sjperkins/seastar,bowlofstew/seastar,stamhe/seastar,avikivity/seastar,anzihenry/seastar,avikivity/scylla,rentongzhang/scylla,kangkot/scylla,guiquanz/scylla,stamhe/scylla,tempbottle/scylla,tempbottle/scylla,bowlofstew/scylla,glommer/scylla,wildinto/seastar,guiquanz/scylla,glommer/scylla,printedheart/seastar,dreamsxin/seastar,leejir/seastar,asias/scylla,eklitzke/scylla,scylladb/scylla-seastar,duarten/scylla,jonathanleang/seastar,phonkee/scylla,kjniemi/seastar,bowlofstew/seastar,raphaelsc/scylla,raphaelsc/scylla,duarten/scylla,shyamalschandra/seastar,koolhazz/seastar,acbellini/scylla,avikivity/seastar,printedheart/seastar,gwicke/scylla,dwdm/scylla,tempbottle/seastar,dwdm/scylla,aruanruan/scylla,norcimo5/seastar,joerg84/seastar,dreamsxin/seastar,glommer/scylla,scylladb/scylla-seastar,hongliangzhao/seastar,rentongzhang/scylla,duarten/scylla,syuu1228/seastar,avikivity/seastar,stamhe/scylla,rluta/scylla,cloudius-systems/seastar,respu/scylla,anzihenry/seastar,bzero/seastar,dwdm/seastar,asias/scylla,gwicke/scylla,dwdm/seastar,senseb/scylla,tempbottle/scylla,shaunstanislaus/scylla,dwdm/scylla,scylladb/scylla,eklitzke/scylla,cloudius-systems/seastar,leejir/seastar,victorbriz/scylla,wildinto/scylla,jonathanleang/seastar,kangkot/scylla,asias/scylla,acbellini/seastar,shaunstanislaus/scylla,wildinto/seastar,linearregression/scylla,syuu1228/seastar,wildinto/scylla,chunshengster/seastar,stamhe/seastar,acbellini/seastar,eklitzke/scylla,printedheart/seastar,xtao/seastar,acbellini/seastar,joerg84/seastar,mixja/seastar,linearregression/seastar,linearregression/seastar,linearregression/seastar,capturePointer/scylla,senseb/scylla,victorbriz/scylla,guiquanz/scylla,mixja/seastar,koolhazz/seastar,victorbriz/scylla,phonkee/scylla,scylladb/scylla,koolhazz/seastar,chunshengster/seastar,acbellini/scylla,avikivity/scylla,hongliangzhao/seastar,raphaelsc/scylla,acbellini/scylla,dreamsxin/seastar,flashbuckets/seastar,chunshengster/seastar,kjniemi/seastar,anzihenry/seastar,scylladb/seastar,norcimo5/seastar,aruanruan/scylla,leejir/seastar,justintung/scylla,xtao/seastar,gwicke/scylla,kjniemi/scylla,shyamalschandra/seastar,capturePointer/scylla,norcimo5/seastar,flashbuckets/seastar,scylladb/scylla-seastar,scylladb/seastar,phonkee/scylla,shaunstanislaus/scylla,capturePointer/scylla,senseb/scylla,rluta/scylla,dwdm/seastar,rentongzhang/scylla,bzero/seastar,hongliangzhao/seastar,sjperkins/seastar,respu/scylla,justintung/scylla,bzero/seastar,scylladb/seastar,sjperkins/seastar,mixja/seastar,bowlofstew/seastar