Use LDFLAGS when compiling ghc-pwd
Use LDFLAGS when compiling ghc-pwd

(cherry picked from commit 2aa78106ae8f3c9b71d7b85c2a8a5558c4c35fb4)

hferreiro/replay,lukexi/ghc-7.8-arm64,hferreiro/replay,hferreiro/replay,lukexi/ghc-7.8-arm64,hferreiro/replay,hferreiro/replay,hferreiro/replay,lukexi/ghc-7.8-arm64,lukexi/ghc-7.8-arm64,lukexi/ghc-7.8-arm64,hferreiro/replay