llvm: create all versioned symlinks for libLLVM on darwin

Apply eb31e481475 to older versions where applicable.

pkgs/development/compilers/llvm/5/llvm.nix

@@ -18,10 +18,13 @@
 let
   src = fetch "llvm" "0g1bbj2n6xv4p1n6hh17vj3vpvg56wacipc81dgwga9mg2lys8nm";
 
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with stdenv.lib;
-    concatStringsSep "." (take 2 (splitString "." release_version));
-in stdenv.mkDerivation (rec {
+  # Used when creating a versioned symlinks of libLLVM.dylib
+  versionSuffixes = with stdenv.lib;
+    let parts = splitString "." release_version; in
+    imap (i: _: concatStringsSep "." (take i parts)) parts;
+in
+
+stdenv.mkDerivation (rec {
   name = "llvm-${version}";
 
   unpackPhase = ''
@@ -119,8 +122,9 @@ in stdenv.mkDerivation (rec {
     substituteInPlace "$out/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
       --replace "\''${_IMPORT_PREFIX}/lib/libLLVM.dylib" "$lib/lib/libLLVM.dylib" \
       --replace "\''${_IMPORT_PREFIX}/lib/libLTO.dylib" "$lib/lib/libLTO.dylib"
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
+    ${stdenv.lib.concatMapStringsSep "\n" (v: ''
+      ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${v}.dylib
+    '') versionSuffixes}
   '';
 
   doCheck = stdenv.isLinux && (!stdenv.isi686);