auto merge of #19285 : alexcrichton/rust/issue-19280, r=aturon
auto merge of #19285 : alexcrichton/rust/issue-19280, r=aturon

It turns out that rustrt::at_exit() doesn't actually occur after all pthread
threads have exited (nor does atexit()), so there's not actually a known point
at which we can deallocate these keys. It's not super critical that we do so,
however, because we're about to exit anyway!

Closes #19280

miniupnp/rust,quornian/rust,bombless/rust,AerialX/rust-rt-minimal,mihneadb/rust,rprichard/rust,rohitjoshi/rust,TheNeikos/rust,andars/rust,mvdnes/rust,pshc/rust,andars/rust,cllns/rust,bombless/rust,quornian/rust,mahkoh/rust,aidancully/rust,ebfull/rust,hauleth/rust,reem/rust,aidancully/rust,andars/rust,rohitjoshi/rust,cllns/rust,aepsil0n/rust,zachwick/rust,emk/rust,ruud-v-a/rust,reem/rust,dwillmer/rust,dinfuehr/rust,carols10cents/rust,XMPPwocky/rust,defuz/rust,XMPPwocky/rust,mdinger/rust,dwillmer/rust,jashank/rust,KokaKiwi/rust,kimroen/rust,jroesch/rust,reem/rust,krzysz00/rust,defuz/rust,GBGamer/rust,emk/rust,mihneadb/rust,mdinger/rust,richo/rust,jroesch/rust,dwillmer/rust,mahkoh/rust,zaeleus/rust,ruud-v-a/rust,sae-bom/rust,kimroen/rust,ktossell/rust,aepsil0n/rust,aidancully/rust,aepsil0n/rust,victorvde/rust,quornian/rust,mvdnes/rust,quornian/rust,jashank/rust,pshc/rust,rprichard/rust,vhbit/rust,nwin/rust,vhbit/rust,nwin/rust,zubron/rust,seanrivera/rust,pelmers/rust,zachwick/rust,rohitjoshi/rust,omasanori/rust,vhbit/rust,sae-bom/rust,zachwick/rust,gifnksm/rust,AerialX/rust,dinfuehr/rust,pelmers/rust,dinfuehr/rust,kimroen/rust,vhbit/rust,pelmers/rust,emk/rust,ejjeong/rust,KokaKiwi/rust,graydon/rust,jashank/rust,ebfull/rust,andars/rust,mahkoh/rust,mdinger/rust,avdi/rust,seanrivera/rust,andars/rust,omasanori/rust,AerialX/rust,untitaker/rust,kimroen/rust,pshc/rust,aneeshusa/rust,avdi/rust,avdi/rust,nwin/rust,aneeshusa/rust,jroesch/rust,seanrivera/rust,untitaker/rust,krzysz00/rust,rohitjoshi/rust,XMPPwocky/rust,GBGamer/rust,richo/rust,victorvde/rust,rprichard/rust,jroesch/rust,zubron/rust,defuz/rust,ktossell/rust,ejjeong/rust,mahkoh/rust,KokaKiwi/rust,cllns/rust,nwin/rust,ejjeong/rust,sae-bom/rust,emk/rust,untitaker/rust,bombless/rust-docs-chinese,robertg/rust,zachwick/rust,ktossell/rust,hauleth/rust,miniupnp/rust,XMPPwocky/rust,robertg/rust,sae-bom/rust,KokaKiwi/rust,rprichard/rust,ktossell/rust,hauleth/rust,kwantam/rust,TheNeikos/rust,kimroen/rust,bombless/rust,victorvde/rust,AerialX/rust,jashank/rust,krzysz00/rust,ejjeong/rust,AerialX/rust-rt-minimal,l0kod/rust,vhbit/rust,quornian/rust,avdi/rust,AerialX/rust,dwillmer/rust,GBGamer/rust,jashank/rust,mahkoh/rust,nwin/rust,robertg/rust,omasanori/rust,dwillmer/rust,l0kod/rust,krzysz00/rust,aepsil0n/rust,richo/rust,zubron/rust,aneeshusa/rust,zubron/rust,mvdnes/rust,GBGamer/rust,untitaker/rust,kwantam/rust,reem/rust,philyoon/rust,GBGamer/rust,kimroen/rust,TheNeikos/rust,philyoon/rust,kwantam/rust,richo/rust,gifnksm/rust,AerialX/rust-rt-minimal,quornian/rust,ejjeong/rust,robertg/rust,untitaker/rust,zubron/rust,kwantam/rust,victorvde/rust,miniupnp/rust,hauleth/rust,seanrivera/rust,ktossell/rust,mvdnes/rust,avdi/rust,mihneadb/rust,ejjeong/rust,gifnksm/rust,dinfuehr/rust,GBGamer/rust,bombless/rust,sae-bom/rust,aidancully/rust,mdinger/rust,miniupnp/rust,zubron/rust,zachwick/rust,cllns/rust,zaeleus/rust,robertg/rust,victorvde/rust,AerialX/rust-rt-minimal,miniupnp/rust,andars/rust,carols10cents/rust,l0kod/rust,kimroen/rust,aneeshusa/rust,defuz/rust,ruud-v-a/rust,krzysz00/rust,richo/rust,dinfuehr/rust,rprichard/rust,zaeleus/rust,aidancully/rust,jashank/rust,quornian/rust,kwantam/rust,cllns/rust,philyoon/rust,jroesch/rust,rohitjoshi/rust,graydon/rust,hauleth/rust,ruud-v-a/rust,aepsil0n/rust,miniupnp/rust,KokaKiwi/rust,miniupnp/rust,aepsil0n/rust,carols10cents/rust,krzysz00/rust,rprichard/rust,nwin/rust,pelmers/rust,pshc/rust,gifnksm/rust,untitaker/rust,pshc/rust,vhbit/rust,ebfull/rust,graydon/rust,l0kod/rust,kwantam/rust,nwin/rust,pelmers/rust,philyoon/rust,l0kod/rust,l0kod/rust,ebfull/rust,TheNeikos/rust,jashank/rust,graydon/rust,cllns/rust,gifnksm/rust,richo/rust,l0kod/rust,rohitjoshi/rust,KokaKiwi/rust,omasanori/rust,emk/rust,ruud-v-a/rust,graydon/rust,mihneadb/rust,aneeshusa/rust,nwin/rust,XMPPwocky/rust,mihneadb/rust,AerialX/rust,emk/rust,ktossell/rust,XMPPwocky/rust,AerialX/rust-rt-minimal,bombless/rust,carols10cents/rust,zachwick/rust,zaeleus/rust,hauleth/rust,philyoon/rust,dwillmer/rust,TheNeikos/rust,avdi/rust,GBGamer/rust,aidancully/rust,victorvde/rust,zubron/rust,sae-bom/rust,mdinger/rust,defuz/rust,mvdnes/rust,defuz/rust,graydon/rust,zaeleus/rust,GBGamer/rust,seanrivera/rust,pshc/rust,AerialX/rust,zubron/rust,ruud-v-a/rust,jroesch/rust,vhbit/rust,gifnksm/rust,reem/rust,carols10cents/rust,TheNeikos/rust,pelmers/rust,ebfull/rust,miniupnp/rust,dwillmer/rust,omasanori/rust,dinfuehr/rust,robertg/rust,mvdnes/rust,philyoon/rust,omasanori/rust,emk/rust,ktossell/rust,pshc/rust,jroesch/rust,dwillmer/rust,mdinger/rust,mihneadb/rust,seanrivera/rust,jashank/rust,zaeleus/rust,bombless/rust,AerialX/rust-rt-minimal,ebfull/rust,vhbit/rust,l0kod/rust,jroesch/rust,pshc/rust,aneeshusa/rust,reem/rust,mahkoh/rust,carols10cents/rust