make bindist packages the wrong binaries for cross compilers

When building binary distributions via make binary-dist, the resulting binaries in the package end up being compiled for the target instead of the host when cross compiling.

E.g. building a cross compiler for iOS on macOS yields:

./inplace/bin/ghc-cabal:                            Mach-O 64-bit executable x86_64
./utils/ghc-cabal/dist/build/tmp/ghc-cabal:         Mach-O 64-bit executable x86_64
./utils/ghc-cabal/dist-install/build/tmp/ghc-cabal: Mach-O 64-bit executable arm64
./inplace/lib/bin/hsc2hs:                     Mach-O 64-bit executable x86_64
./utils/hsc2hs/dist/build/tmp/hsc2hs:         Mach-O 64-bit executable x86_64
./utils/hsc2hs/dist-install/build/tmp/hsc2hs: Mach-O 64-bit executable arm64

to just name ghc-cabal and hsc2hs.

Trac metadata

Trac field	Value
Version	8.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	high
Resolution	Unresolved
Component	Package system
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	bgamari
Operating system
Architecture