Rollup merge of #35433 - mneumann:dragonfly-fix-libstd-errno-location, r=alexcrichton
Rollup merge of #35433 - mneumann:dragonfly-fix-libstd-errno-location, r=alexcrichton

Fix build on DragonFly (unused function errno_location)

Function errno_location() is not used on DragonFly. As warnings are
errors, this breaks the build.

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