llvmPackages_3.7: fix libnames output of llvm-config

see also 4c4f50ce76

pkgs/development/compilers/llvm/3.7/fix-llvm-config.patch

@@ -0,0 +1,13 @@
+diff --git a/utils/llvm-build/llvmbuild/main.py b/utils/llvm-build/llvmbuild/main.py
+index eacefdf60bf..40d25f5cef8 100644
+--- a/utils/llvm-build/llvmbuild/main.py
++++ b/utils/llvm-build/llvmbuild/main.py
+@@ -412,7 +412,7 @@ subdirectories = %s
+             if library_name is None:
+                 library_name_as_cstr = '0'
+             else:
+-                library_name_as_cstr = '"lib%s.a"' % library_name
++                library_name_as_cstr = '"lib%s.so"' % library_name
+             f.write('  { "%s", %s, %d, { %s } },\n' % (
+                 name, library_name_as_cstr, is_installed,
+                 ', '.join('"%s"' % dep

pkgs/development/compilers/llvm/3.7/llvm.nix

@@ -53,6 +53,11 @@ in stdenv.mkDerivation rec {
     ln -sv $PWD/lib $out
   '';
 
+  patches = stdenv.lib.optionals (!stdenv.isDarwin) [
+    # llvm-config --libfiles returns (non-existing) static libs
+    ./fix-llvm-config.patch
+  ];
+
   cmakeFlags = with stdenv; [
     "-DCMAKE_BUILD_TYPE=${if debugVersion then "Debug" else "Release"}"
     "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc