treewide: remove redundant rec

pkgs/development/compilers/llvm/8/compiler-rt.nix

@@ -1,5 +1,5 @@
 { stdenv, version, fetch, cmake, python, llvm, libcxxabi }:
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "compiler-rt";
   inherit version;
   src = fetch "compiler-rt" "0dqqf8f930l8gag4d9qjgn1n0pj0nbv2anviqqhdi1rkhas8z0hi";

pkgs/development/compilers/llvm/8/default.nix

@@ -145,7 +145,7 @@ let
       '' + mkExtraBuildCommands cc;
     };
 
-    lldClangNoCompilerRt = wrapCCWith rec {
+    lldClangNoCompilerRt = wrapCCWith {
       cc = tools.clang-unwrapped;
       libcxx = null;
       bintools = wrapBintoolsWith {

pkgs/development/compilers/llvm/8/libc++/default.nix

@@ -1,7 +1,7 @@
 { lib, stdenv, fetch, cmake, python, libcxxabi, fixDarwinDylibNames, version
 , enableShared ? true }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "libc++";
   inherit version;
 

pkgs/development/compilers/llvm/8/llvm.nix

@@ -27,7 +27,7 @@ let
   shortVersion = with stdenv.lib;
     concatStringsSep "." (take 1 (splitString "." release_version));
 
-in stdenv.mkDerivation (rec {
+in stdenv.mkDerivation ({
   name = "llvm-${version}";
 
   src = fetch "llvm" "1rvm5gqp5v8hfn17kqws3zhk94w4kxndal12bqa0y57p09nply24";