Auto merge of #55051 - matthiaskrgr:dist_msg, r=Mark-Simulacrum
Auto merge of #55051 - matthiaskrgr:dist_msg, r=Mark-Simulacrum

boostrap: dist: if a file cannot be installed because it does not exist, print its name in the error message.

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