Clang toolchain: use lld to compile LLVM Gold plugin and lld with LTO.

tools/clang/scripts/package.py

Index: tools/clang/scripts/package.py
diff --git a/tools/clang/scripts/package.py b/tools/clang/scripts/package.py
index fb958605f4c8909426351c0605be3786b24f2a17..acb31df39617aad916832b4abbebb54e50df10fd 100755
--- a/tools/clang/scripts/package.py
+++ b/tools/clang/scripts/package.py
@@ -178,7 +178,7 @@ def main():
 
     opt_flags = []
     if sys.platform.startswith('linux'):
-      opt_flags += ['--lto-gold-plugin']
+      opt_flags += ['--lto']
     build_cmd = [sys.executable, os.path.join(THIS_DIR, 'update.py'),
                  '--bootstrap', '--force-local-build',
                  '--run-tests'] + opt_flags
@@ -217,6 +217,7 @@ def main():
                  'lib/clang/*/lib/darwin/*profile_osx*',
                  ])
   elif sys.platform.startswith('linux'):
+    want.append('bin/lld')
     # Copy the libstdc++.so.6 we linked Clang against so it can run.
     want.append('lib/libstdc++.so.6')
     # Copy only