bootstrap: tidy up flag handling for llvm build#93918

Merged

bors merged 2 commits intorust-lang:masterfrom jonhoo:bootstrap-native-envflags

Feb 15, 2022

+66-31

Commits on Feb 12, 2022

bootstrap: make LLVM build respect *FLAGS envvars
Jon Gjengset
committed
bootstrap: -static-libstdc++ is a linker flag
Jon Gjengset
committed