gcc-*: homogenize and cleanup expressions with a mass rebuild

pkgs/development/compilers/gcc/7/default.nix

@@ -207,12 +207,9 @@ stdenv.mkDerivation ({
     targetPackages.stdenv.cc.bintools # For linking code at run-time
   ] ++ (optional (isl != null) isl)
     ++ (optional (zlib != null) zlib)
-    ++ (optionals (targetPlatform != hostPlatform) [targetPackages.stdenv.cc.bintools])
-
     # The builder relies on GNU sed (for instance, Darwin's `sed' fails with
     # "-i may not be used with stdin"), and `stdenvNative' doesn't provide it.
     ++ (optional hostPlatform.isDarwin gnused)
-    ++ (optional hostPlatform.isDarwin targetPackages.stdenv.cc.bintools)
     ;
 
   NIX_CFLAGS_COMPILE = stdenv.lib.optionalString (stdenv.cc.isClang && langFortran) "-Wno-unused-command-line-argument";