add get* helper functions and mass-replace manual outputs search with them

pkgs/development/compilers/gcc-arm-embedded/default.nix

@@ -33,8 +33,8 @@ stdenv.mkDerivation {
 
     for f in $(find $out); do
       if [ -f "$f" ] && patchelf "$f" 2> /dev/null; then
-        patchelf --set-interpreter ${glibc.out}/lib/ld-linux.so.2 \
-                 --set-rpath $out/lib:${gcc.lib or gcc}/lib:${ncurses.out}/lib \
+        patchelf --set-interpreter ${getLib glibc}/lib/ld-linux.so.2 \
+                 --set-rpath $out/lib:${getLib gcc}/lib:${ncurses.out}/lib \
                  "$f" || true
       fi
     done

pkgs/development/compilers/ghc/6.10.2-binary.nix

@@ -1,4 +1,4 @@
-{stdenv, fetchurl, perl, libedit, ncurses, gmp}:
+{stdenv, lib, fetchurl, perl, libedit, ncurses, gmp}:
 
 stdenv.mkDerivation rec {
   version = "6.10.2";
@@ -47,7 +47,7 @@ stdenv.mkDerivation rec {
      '' else "");
 
   configurePhase = ''
-    ./configure --prefix=$out --with-gmp-libraries=${gmp.out}/lib --with-gmp-includes=${gmp.dev or gmp}/include
+    ./configure --prefix=$out --with-gmp-libraries=${lib.getLib gmp}/lib --with-gmp-includes=${lib.getDev gmp}/include
   '';
 
   # Stripping combined with patchelf breaks the executables (they die

pkgs/development/compilers/go/1.4.nix

@@ -58,7 +58,7 @@ stdenv.mkDerivation rec {
     sed -i 's,/usr/share/zoneinfo/,${tzdata}/share/zoneinfo/,' src/time/zoneinfo_unix.go
 
     # Find the loader dynamically
-    LOADER="$(find ${libc.out or libc}/lib -name ld-linux\* | head -n 1)"
+    LOADER="$(find ${lib.getLib libc}/lib -name ld-linux\* | head -n 1)"
 
     # Replace references to the loader
     find src/cmd -name asm.c -exec sed -i "s,/lib/ld-linux.*\.so\.[0-9],$LOADER," {} \;