hadrian: fix _build/ghc-stage1 to make it callable from any directory
It does so by simply writing down the complete path to the stage 0 compiler, instead of assuming the script is called from the top of the GHC source tree.
Before:
"_build/stage0/bin/ghc" "-package-db _build/stage1/lib/package.conf.d" "$@"After:
"/home/alp/ghc/_build/stage0/bin/ghc" "-package-db _build/stage1/lib/package.conf.d" "$@"