Rollup merge of #64541 - RalfJung:miri-errors, r=oli-obk
Rollup merge of #64541 - RalfJung:miri-errors, r=oli-obk

document Miri error categories

r? @oli-obk

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