Rollup merge of #67256 - RalfJung:reduce-allocs, r=oli-obk
Rollup merge of #67256 - RalfJung:reduce-allocs, r=oli-obk

Reduce allocs for validation errors

This probably doesn't really matter, but I just felt like I had to do this...

r? @oli-obk

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