Rollup merge of #45882 - japaric:gh45802, r=kennytm
Rollup merge of #45882 - japaric:gh45802, r=kennytm

fix core for targets with max-atomic-width = 0

closes #45802

cc @kennytm

aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust