llvmPackages_git.libclc: init

pkgs/development/compilers/llvm/git/default.nix

@@ -274,6 +274,12 @@ in let
       nixSupport.cc-cflags = [ "-fno-exceptions" ];
     });
 
+    # Has to be in tools despite mostly being a library,
+    # because we use a native helper executable from a
+    # non-cross build in cross builds.
+    libclc = callPackage ../common/libclc.nix {
+      inherit buildLlvmTools;
+    };
   });
 
   libraries = lib.makeExtensible (libraries: let